No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Pulsed electrodeposition of Zn in the presence of surfactants
Abstract
The preparation of Zn deposits has been performed by galvanostatic pulsed electrolysis, from acidic zinc sulphate solutions, on a stainless steel substrate. The influence of the surfactants (cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS) and octylphenolpoly(ethyleneglycolether)n, n = 10, Triton X-100) on the voltammetric behaviour, structural and morphological characteristics of the deposits have been investigated. The characterization of the samples was made by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS). The experimental data shows that the presence of surfactants affects the zinc deposition process. The electrodeposits are mainly composed by Zn with different texture, crystal shape and size (grain size ranging from 40 to 20 nm). The obtained results led us to conclude that the Zn deposits prepared in the absence of surfactants and in the presence of SDS are more crystalline and with a higher grain size than the ones obtained in the presence of CTAB and Triton X-100. These facts may be justified by the increase on the overpotential deposition as the electrochemical studies confirm.The XRD results show that the deposits prepared, in the absence of surfactant and in the presence of SDS, contain ZnSO4 and Zn4SO4(OH)6 as oxidation products. ZnO is also detected on the deposits obtained in the presence of CTAB and Triton X-100.
... Many studies have been interested by the effects of electrolysis parameters, such as pH value and current density, on the crystallographic texture and surface morphology of zinc deposits on a steel substrate [11,12,18]. Besides, calculations and experimental determinations of some electrochemical parameters for Zn/Zn(II) on different electrodes are presented [2,3,8,9,12,16,[19][20][21]. ...
... Gomes et al. [16] had realized a pulsed electrodeposition of Zinc in acidic sulphate solutions. The morphological and structural analysis showed that the Zn deposition is accompanied by the evolution and adsorption of hydrogen bubbles and in consequence the surface was not uniform. ...
... With higher current density (− 40 mA cm −2 ) a flower-like shape is observed (Fig. 5d), with a transient from bidimensional to tridimensional structure. However, the heterogeneous structure and the random growing of the nanograins provides a dull and rough deposit [5,16,[27][28][29][30][31][32]. ...
A three-electrode electrochemical cell was used for the optimization of bath constituents and parameters. Galvanostatic electrodeposition from a free additives bath, combining sulfate and chloride compounds results in bright Zn deposits with high corrosion resistance. Surface morphology was observed by scanning electron microscopy, chemical and phase composition were determined by X-ray diffraction, and corrosion investigations by electrochemical techniques. Electrochemical impedance spectroscopy (EIS) and polarization measurements revealed that the electrodeposited Zn coating with the higher current density and pH value had the best corrosion resistance. Bright and uniform surface appearance, of Zn deposits, with a platelet structure, moderate current efficiency and a high corrosion resistance was obtained at a pH of 4.5 and a current density of 16 mA cm⁻².
... In addition, this work shows that the Zn anodes with dominant (101) and (100) crystallographic orientations are prone to dendrite formation, while those with dominant (002) and (103) planes are less likely. 125 However, this conclusion is different from some previous studies, 144,145 where they demonstrated the electrodeposited Zn anode without organic additives possesses a strong (002) texture, and the introduction of additives would change the preferred orientation from the basal (002) plane to (100) and (110). 144 One thing these studies are in agreement with is that by introducing surface modifiers, crystallographic orientations of the electrodeposited Zn will be altered. ...
... 125 However, this conclusion is different from some previous studies, 144,145 where they demonstrated the electrodeposited Zn anode without organic additives possesses a strong (002) texture, and the introduction of additives would change the preferred orientation from the basal (002) plane to (100) and (110). 144 One thing these studies are in agreement with is that by introducing surface modifiers, crystallographic orientations of the electrodeposited Zn will be altered. This is because the organic surfactants will block some of the active sites and possess electrostatic interactions with Zn 2+ , therefore inducing different growth kinetics during the Zn electrodeposition process. ...
... This is because the organic surfactants will block some of the active sites and possess electrostatic interactions with Zn 2+ , therefore inducing different growth kinetics during the Zn electrodeposition process. 144 Future studies may also consider exploring the effects of inorganic additives on the surface morphology and crystal texture of the electroplated zinc anodes. This strategy, although effective, is not applicable for large scale application because of the toxicity and high price of most additives. ...
Aqueous zinc ion batteries (ZIBs) are truly promising contenders for the future large-scale electrical energy storage applications due to their cost-effectiveness, environmental friendliness, intrinsic safety, and competitive gravimetric energy density. In light of this, massive research efforts have been devoted to the design and development of high-performance aqueous ZIBs; however, there are still obstacles to overcome before realizing their full potentials. Here, the current advances, existing limitations, along with the possible solutions in the pursuit of cathode materials with high voltage, fast kinetics, and long cycling stability are comprehensively covered and evaluated, together with an analysis of their structures, electrochemical performance, and zinc ion storage mechanisms. Key issues and research directions related to the design of highly reversible zinc anodes, the exploration of electrolytes satisfying both low cost and good performance, as well as the selection of compatible current collectors are also discussed, to guide the future design of aqueous ZIBs with a combination of high gravimetric energy density, good reversibility, and a long cycle life.
... Gomes et al. [24] indicated that anionic surfactant SDS can adsorb on the growing zinc deposit and block the electrocrystallization process. This inhibition depends on the size of the organic molecules and the specific interactions between the surfactant and the substrate. ...
... Moreover, the addition of Triton X-100 may lead to the formation of ZnO. It may be due to the blocking effect of surfactants molecules adsorbed on the metal surface, which causes shift of deposition potential toward more negative values, and then result in the incomplete reduction of ZnO [24]. ...
... They reported that CTAB enhanced the nucleation rate and retardation in crystal growth leading to the smaller crystallite size of the deposit [19]. The influence of CTAB on the decrease of the crystallite size of the deposit was also confirmed by Gomes et al. [24], Mehta et al. [35] and Maharana et al. [36]. CTAB is a cationic surfactant that has a positive Table 1 The organic additives examined e basic data, abbreviations and their role in electrodeposition of zinc. ...
The influence of various additives on the process of electrodeposition of Zn–Mo coatings from citrate solutions was examined. Potentiostatic deposition, Wavelength dispersive X-ray fluorescence (WDXRF), X-ray diffraction and micro-Raman spectroscopy were carried out to analyze the role surfactants of electrodeposition of Zn–Mo layers. Atomic force microscopy was applied to investigate the surface morphologies. The mechanism describing the action of surfactant during the co-deposition process of Zn–Mo has been proposed. It was found that the additive can adsorb specifically on the Inner Helmholtz Plane (IHPs) on the cathode and consequently limiting the approaching of other molecules (complexes) to the surface. Reduction processes are associated mainly with the formation and adsorption of zinc citrate complexes and mixed Zn(I)–Mo(VI)-citrate complexes those further reduce to metallic zinc and metallic zinc-molybdenum alloy (two hexagonal metallic phases). What is remarkable by hindering the reduction of the Zn(I)-citrate complex, the surfactant inhibits the reduction of zinc to metallic zinc and at the same time facilitates (catalyzes) the formation of the Zn(I)–Mo(VI)-citrate complex. The presence of only PEG 20000 in the bath causes deposition of one (Zn,Mo) hcp phase. While the presence in the bath of CTAB, Triton X-100 or D-sorbitol makes that two hcp phases can create: (Zn) and (Zn,Mo) or one hcp phase (Zn) and one oxide phase (MoO2).
However, absence of surfactants or not optimal concentration of surfactants in the electrolyte and low ratio of concentrations of Zn(II) to Mo(VI) cause the reduction of molybdenum complexes only to molybdenum oxides which blocked the cathode surface, when in the case of greater ratio of concentrations of Zn(II) to Mo(VI) (increase the reduction rate of zinc citrate complexes in comparison to mixed Zn(I)–Mo(VI)-citrate complexes and molybdate citrate complexes ([(MoO4)H3cit]³⁻)) the metallic zinc, zinc oxides, and molybdenum oxides can co-deposit on the electrode surface (composite coatings of oxide nanoparticles dispersed within a zinc matrix).
... The polarization curves produced with baths I to IX showed a gentle slope in red tion current (region E1), followed by a rapid increase in reduction current (region E2) w increasing potential. Other studies have attributed region E1 to the formation of an oxide/hydroxide [17,30] or zinc oxide/hydroxide [31,32] layer on the cathode. The for reason seems unlikely in this study due to the predeposition of zinc on the working e trode prior to the polarization scan. ...
... The polarization curves produced with baths I to IX showed a gentle slope in reduction current (region E 1 ), followed by a rapid increase in reduction current (region E 2 ) with increasing potential. Other studies have attributed region E 1 to the formation of an iron oxide/hydroxide [17,30] or zinc oxide/hydroxide [31,32] layer on the cathode. The former reason seems unlikely in this study due to the predeposition of zinc on the working electrode prior to the polarization scan. ...
Organic additives are required for alkaline zincate plating baths to obtain an acceptable coating on steel for corrosion protection. The effects and possible interactions of three commercial additives (Eldiem Carrier, Eldiem Booster, and Bright Enhancer 2× on zinc electrodeposition from a high-concentration alkaline zincate bath were investigated. Visually acceptable deposits were produced within the current density range of 130 to 430 A m−2 for most additive conditions examined. Over concentration ranges examined, decreasing the booster concentration led to brighter zinc deposits, and an interaction between the carrier and the booster was detected. The additives fostered the formation of compact and adherent coatings as illustrated by scanning electron microscopy. Throwing power and current efficiency were not impacted by the additives over the concentration ranges examined. Linear sweep voltammetry proved that the additives increased the overpotential for zinc deposition. The additive combination that produced the brightest deposit also demonstrated the strongest adsorption of additives in linear sweep voltammetry.
... In Fig. 4b, the crystal orientations of ZB were mainly (1 0 1) and (1 0 3). Other effective planes are (1 0 2), (1 0 0), (0 0 2) and (1 1 0), which was consistent with the literatures [60,61]. But ZS, ZM and ZMS showed different preferential crystallographic orientations with the strongest orientation of (1 0 1), which was revalant to high current efficiency discussed by Mackinnon and Fenn [62]. ...
Photocatalytic MoS2 with visible light response is considered as a promising bactericidal material owing to its non–toxicity and high antibacterial efficiency. However, photocatalysts always exist as powder, so it is difficult to settle photocatalysts on the metal surface, which limits their application in aqueous environments. To solve this problem, ultrasound and sodium dodecyl sulfate (SDS) were introduced into the co-deposition process of MoS2 and zinc matrix, so that novel MoS2–Zn coatings were obtained. In this process, ultrasound and SDS strongly promoted the dispersion and adsorption of MoS2 on the co-depositing surfaces. Then MoS2 were proved to be composited into the Zn matrix with effective structures, and the addition of SDS effectively increased the loading content of MoS2 in the MoS2–Zn coatings. Besides, the antibacterial performance of the MoS2–Zn coatings was evaluated with three typical fouling bacteria E.coli, S.aureus and B.wiedmannii. The MoS2–Zn coating showed high and broad–spectrum antibacterial properties with over 98 % inhibition rate against these three bacteria. Furthermore, it is proved that the MoS2–Zn coatings generated superoxide (·O2⁻) and hydroxyl radicals (·OH) under visible light, which played the dominant and subordinate roles in the antibacterial process, respectively. The MoS2–Zn coatings also showed high antibacterial stability after four “light–dark” cycles. According to the results of the attached bacteria, the MoS2–Zn coatings were considered to effectively repel the living pelagic bacteria instead of killing the attached ones, which was highly environmentally friendly. The obtained MoS2–Zn coatings were considered promising in biofilm inhibiting and marine antifouling fields.
... Voltammetric measurements have been used as an exploratory technique to assess the effect of both commercial and proposed additives on the ED mechanism of Zn. Moreover, the blocking effect, due to Zn additives adsorption on the steel surface, is estimated from I values measured in the presence and absence of the organic molecules [8,16]. Herein, LSV measurements were performed to identify the different stages in ED processes, labeled C1, C2 and C3 (underpotential, nucleation and massive deposition zones, respectively). ...
... On the other hand, Gomes et al. [109] also prepared zinc deposits by electrodeposition of PC from acid solutions of zinc sulphate on stainless steel. These authors focused on studying the influence of anionic (sodium dodecylsulphate, SDS), cationic (cetyltrimethylammonium bromide, CTAB) and non-ionic (octylphenolpoly(ethylene glycol ether)n, n = 10, Triton X-100) surfactants on the morphological characteristics of the electrodeposited coatings. ...
The improvement of biodegradable metals is currently an active and promising research area for their capabilities in implant manufacturing. However, controlling their degradation rate once their surface is in contact with the physiological media is a challenge. Surface treatments are in the way of addressing the improvement of this control. Zinc is a biocompatible metal present in the human body as well as a metal widely used in coatings to prevent corrosion, due to its well-known metal protective action. These two outstanding characteristics make zinc coating worthy of consideration to improve the degradation behaviour of implants. Electrodeposition is one of the most practical and common technologies to create protective zinc coatings on metals. This article aims to review the effect of the different parameters involved in the electrochemical process on the topography and corrosion characteristics of the zinc coating. However, certainly, it also provides an actual and comprehensive description of the state-of-the-art of the use of electrodeposited zinc for biomedical applications, focusing on their capacity to protect against bacterial colonization and to allow cell adhesion and proliferation.
... Pulse electrophoretic deposition (EPD) has been commonly used to improve electrophoretic deposition uniformity, adhesion, and speed [10,11]. Pulse EPD allows for more inert particles to be incorporated into the deposit, which affects the nucleation centers and contributes to grain refining and deposit compactness [12].Pulsed EPD carried out in a two-electrode cell, substrates were 316L stainless steel plates with the dimension of (15×15×10) mm which only 1.8 cm 2 of them was exposed to deposition, and the remainder was insulated. ...
The aim of this research is to create a chitosan/hydroxyapatite composition coating for biomedical applications. The effect was studied of the solution suspension and the pulsed current electrophoretic deposition on the coating composite. The 316L SS. alloys was coated by the pulsed EPD technique with hydroxyapatite in a solution containing 0.15, 0.3, 0.45 and 0.6 mg nano hydroxyapatite in 100 mL of suspension and at constant voltage 30 V. X-ray diffraction spectroscopy (XRD), Scanning electron microscope (SEM), and Fourier transform infrared (FTIR), also the mechanical tests including micro hardness and micro roughness were performed to characterize the deposited coatings.
... Keywords: hydronium ion, cathode, zinc, copper, aluminum, Tafel slope, potential, hydrogen discharge, steady state potential, exchange current, apparent transfer coefficients. [16], на реакцию разряда водорода и ряда металлов в сульфатных [17,18], хлоридных и спиртовых растворах, рассматривая при этом поведение поверхностно-активных веществ (ПАВ) в указанных процессах [19,20]. Такое влияние на разряд катионов присутствия в растворе лигносульфоната и лигнина отмечено в работах [21,22]. ...
Electrochemical reduction of hydrogen (hydronium ion) was carried out on zinc, aluminum and copper cathodes from acidic aqueous solutions containing sulfuric acid (0.09, 0.18 and 0.36 mol/l) to study the effect of electrolyte acidity, the type of cathodes used and potential values on electrolysis indicators. The studies were carried out on the potentiostat using a three-electrode cell under conditions of intensive electrolyte stirring with a magnetic stirrer. At the initial stage, electrolysis was performed in the following modes: potentiodynamic measurements at a sweep rate of 1 mV/s in the potential range Е = –(700÷850) mV on a copper and aluminum electrode and Е = –(1000÷1150) mV on a zinc electrode. In the indicated potential range, hydronium discharge parameters at each cathode were calculated: Tafel slope, apparent transfer coefficients and exchange currents. Dependences of these parameters on electrolyte acidity were considered. Average values of steady state potentials were obtained, which, similar to the apparent exchange current, significantly depended on the cathode material: –923.1 mV (zinc cathode); +36.1 mV (copper cathode), and –603.7 mV (aluminum cathode) (AgCl/Ag). The effect of surfactants on all the kinetic parameters considered was shown. The order of the reaction with and without surfactant additives was determined. At the next stage, the electrochemical parameters of hydronium discharge on the copper electrode only were compared. It was shown that the electrochemical parameters significantly depend on the cathodic potential range where they are determined, and on the methods used for their calculation. It was noted that the process proceeds in the region of mixed kinetics. As the electrode polarization decreases, the hydrogen discharge mechanism changes, while the proportion of electrochemical kinetics will increase in the region of mixed kinetics. We suppose that the data obtained can also be of practical importance for the zinc electrolysis technology. The data obtained in this research on the electrochemical parameters of hydrogen discharge in a wide range of potentials on cathodes made of different metals as well as on the effect of electrolyte acidity on the behavior of surfactants during electrolysis will expand knowledge about the zinc electrolysis technology.
... Additionally, they are giving more attention to modifying cathodes, which can enhance the electrochemical performance. Materials with a spinel or layer structure, such as Mn-based, vanadiumbased, and Prussian blue analogous, are attracting attention for modifying electrode materials for AZIBs [11,[21][22][23][24][25][26][27][28]. Among them, Mn-based materials have gained a lot of interest in the cathode materials because of their diverse crystal structures, different valence states, and high-voltage platforms [26,[29][30][31][32]. First, alkaline electrolytes acting as primary electrolytes were used in Mn-based materials in the 1860s. ...
Lithium-ion batteries (LIBs) have been considered an easily accessible battery technology because of their low weight, cheapness, etc. Unfortunately, they have significant drawbacks, such as flammability and scarcity of lithium. Since the components of zinc-ion batteries are nonflammable, nontoxic, and cheap, AZIBs could be a suitable replacement for LIBs. In this article, the advantages and drawbacks of AZIBs over other energy storage devices are briefly discussed. This review focused on the cathode materials and electrolytes for AZIBs. In addition, we discussed the approaches to improve the electrochemical performance of zinc batteries. Here, we also discussed the polymer gel electrolytes and the electrodes for flexible zinc-ion batteries (FZIBs). Moreover, we have outlined the importance of temperature and additives in a flexible zinc-ion battery. Finally, we have discussed anode materials for both AZIBs and FZIBs. This review has summarized the advantages and disadvantages of AZIBs and FZIBs for future applications in commercial battery technology.
... 16 The addition of cetyltrimethylammonium bromide (CTAB) and Triton X-100 surfactants during the electrodeposition of zinc resulted in smaller grain size particles than those particles obtained in the absence of any surfactants or in the presence of sodium dodecyl sulfate (SDS). 17 In another study, the introduction of NaI to a solution of AlCl 3 -NaCl-KCl molten salts for the electrodeposition of aluminum resulted in the formation of much smaller particles. 18 Different capping agents can interact preferentially with specific facets of NPs, which opens the door to a wide range of potential morphologies from nanocubes to nanorods to nanoprisms. ...
Optimizing platinum (Pt) utilization is a necessary step towards developing affordable electrocatalysts for fuel cells and related technologies. Electrodeposition is a scalable approach to preparing Pt nanoparticles (NPs). Herein, Cl ⁻ and Br ⁻ ions are used in excess as additives during the electrodeposition of Pt NPs to influence nucleation and growth processes as a means of tuning particle morphology and their electrocatalytic activity. Adding NaCl formed larger particles with urchin-like morphologies while adding NaBr produced smaller, more uniform NPs that were evenly dispersed across the substrate. Mixtures of these two halide ion species improved surface coverage and size distribution of the NPs. Particle size was further decreased, and their surface coverage increased by combining the addition of excess halide ions with using a higher applied potential to initiate ‘nucleation’ followed by a lower applied potential to promote particle ‘growth’. Mass activity towards the oxygen reduction reaction was the highest for Pt NPs electrodeposited in the presence of Br ⁻ . The addition of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide during electrodeposition produced small NPs with an even higher mass activity, which was attributed to the formation of porous nanostructures. This study demonstrates techniques to improve Pt utilization and electrocatalytic activity of electrodeposited Pt NPs.
... Meanwhile, according to a series of current transients at different overpotentials, they demonstrated that Cu deposition in ethaline follows 3D instantaneous nucleation and growth mechanism at large overpotentials. Yet effects of surfactants on metal electrodeposition in DESs are rarely investigated to date, although surfactant or additive addition is essential to improve deposits quality in aqueous solution [28][29][30]. In addition, water addition has been an effective measure to promote electro-reductive reaction of metal ions. ...
Deep eutectic solvents (DESs) are attractive due to their advantages as solvents and electrolytes. Self-aggregation of surfactants would affect physico-chemical properties of DESs and thus electrochemical behavior of electroactive species in DESs. Aggregation behavior of sodium dioctyl sulfosuccinate (AOT) in choline chloride-ethylene glycol mixture containing 4 wt.% water (ethaline-4% H2O) was evaluated by surface-tension measurement. And surfactant effects on electrochemical behavior of copper ions in ethaline-4% H2O electrolyte were investigated by viscosity and ionic conductivity measurements, electrochemical experiments, and morphology analysis. The results show that critical micelle concentration value is 5.32 mM, and viscosity of ethaline-4% H2O increases upon increase of AOT concentration, while ionic conductivity decreases. Two redox couples relating to Cu(II)/Cu(I) and Cu(I)/Cu(0) from cyclic voltammograms were observed at both GCE and Pt electrodes. Using cyclic voltammograms of copper ions at Pt, diffusion coefficients and rate constants of Cu(II) were calculated and found to decrease when AOT concentration increases from 0 to 20 mM. Nucleation and growth processes are fitted well with instantaneous nucleation mode regardless of AOT concentrations from chronoamperometric data of Cu(I)/Cu(0) at GCE. Furthermore, scanning electronic microscopy analysis indicates that aggregation of surfactant AOT near critical micelle concentration plays important role in copper morphology control.
... The sample was then rinsed with deionized water for the 30 s and quickly dried with N 2 for experimentation. Two platinum plate counter electrodes were placed at both sides of the copper foil to achieve uniform deposition of metal zinc at 0.05 A/cm 2 for 450 s in aqueous solution containing 0.6 mol/L ZnSO 4 , 0.1 mol/L (NH 4 ) 2 SO 4 and 0.0005 mol/L sodium dodecyl sulfate (SDS) [56] after 15 min N 2 bubbling, and the bubble was continued during the experiment. The obtained samples were rinsed with deionized water and then blow-dried with N 2 quickly for later use. ...
Microstructures and tensile properties are essential for the practical application of nanoporous copper (NPC), especially in areas of high request to pore distribution and tension. In this work, a novel self-supporting NPC foil (NPC@Cu@NPC) was fabricated through alloying-dealloying method in situ. The results showed that the self-supporting structure provided a tensile strength of about 370 MPa for the NPC@Cu@NPC. When the dealloying temperature changed from 323.15 to 363.15 K, the diffusion rate of copper atoms in the dealloying process increased from 8.970 × 10−17 to 1.610 × 10−15 m2/s, resulting in a significant coarsening of nanoporous ligament along with increase of elongation from 1.53 to 2.73%. The diffusion growth model revealed the quantitative relationship between dealloying temperature (T) and ligament width (d) (ln(d) was proportional to 1/T). The rapid diffusion of copper atoms at high dealloying temperatures could coarsen the ligaments of the nanoporous structure and increase the fracture elongation. In addition, NPC@Cu@NPC had a higher electrochemical active surface area (ECSA) (85.31 cm2) and lower internal charge transfer resistance (Rct) (9.97 Ω) than the flat copper foil (ECSA = 3.5 cm2, Rct = 71.8 Ω). Thus, NPC@Cu@NPC, with more electrochemical active sites and higher electron transport efficiency, has potential application prospects in electrocatalysis and secondary batteries.
... Previous works have shown that the corrosion rate is closely related to the morphology of Zn deposition and the major crystalline surface exposed [122]. Closely packed crystal planes, such as hexagonal close-packed (hcp) Zn (002) planes, have a trend towards higher corrosion resistance [123][124][125][126][127]. In addition, deposited layers with finer crystal sizes possess higher resistance to corrosion [128][129][130][131]. Organic and inorganic additives generally modify the morphology of Zn electrodeposits and endow electrodeposits with superior corrosion resistance [132][133][134][135][136][137]. ...
Safe and low-cost zinc-based flow batteries offer great promise for grid-scale energy storage, which is the key to the widespread adoption of renewable energies. However, advancement in this technology is considerably hindered by the notorious zinc dendrite formation that results in low Coulombic efficiencies, fast capacity decay, and even short circuits. In this review, we first discuss the fundamental mechanisms of zinc dendrite formation and identify the key factors affecting zinc deposition. Then, strategies to regulate zinc deposition are clarified and discussed based on electrode, electrolyte, and membrane. The underlying mechanisms, advantages, and shortcomings of each strategy are elaborated. Finally, the remaining challenges and perspectives of zinc-based flow batteries are presented. The review may provide promising directions for the development of dendrite-free zinc-based flow batteries.
... Moreover, the Zn-ions got entangled with the carbonyl functional groups of PAM with restricted transport blocking active water molecules that afforded dendrite-free cycling of Zn anode with excellent cycling stability [131]. The organic compounds that can be applied as electrolyte additives for the suppression of Zn dendrites include ammonium compounds, surfactants, carbohydrates, organic acids, aldehydes and alcohols etc. [84,126,129,[132][133][134][135][136][137]. Organic compounds can adsorb at the dendritic sites/tips and blocks their further growth and propagation [129,138,139]. ...
Zn batteries receive substantial commendation, due to their inherent safety, environmental benignity and low toxicity. However, poor rechargeability of Zn anode have seriously hindered the applications of rechargeable Zn batteries. The challenges induced by thermodynamic instability of Zn in aqueous electrolytes include dendrites, passivation, corrosion (H2 evolution) and shape change. Since Zn anode is the critical aspect in determining the battery performance, cycle life, energy density and capacity retentions etc. The target of this review is to devote the prominent status to Zn metal anode by firstly explicating the previously studied Zn electrochemistry in different electrolyte systems like aqueous (acidic, alkaline, mildly acidic and neutral), non-aqueous (organic, ionic liquids) electrolytes, and then suggesting some ideas to amend Zn anode reversibility and stability. Because of higher thermodynamic Zn stability in organic electrolytes and recent promisingly improved performance of Zn metal anode, we mark organic electrolytes, particularly with intrinsic safe organic solvents as a promising research direction for high-performance zinc ion batteries (ZIBs).
... It has also been studied for protecting stainless steel. For example, electrolytic baths containing ZnSO 4 have been used to electrochemically coat 316L and 316 stainless steel grades [17,22]. ...
Zinc electroplating was used to enhance corrosion resistance of porous metal injection molded 440C stainless steel. Controlled porosity was achieved by the powder space holder technique and by using sodium chloride as a space holder material. The internal pore structure of porous 440C was deposited by zinc using electroplating with three different electrolytes of zinc acetate, zinc sulfate, and zinc chloride. Our results show that all zinc depositions on porous 440C samples significantly improved corrosion resistance. The lowest corrosion was observed with zinc acetate at 30 wt.% porosity. The developed zinc coated porous 440C samples have potential in applications in corrosive environments.
... Shitanda et al. [129] report that creating a dot-pattern on the substrate surface at the nano-level yields dendrites only where the dots are located on the substrate surface, while Koda et al. [130] note that dendrite formation can be suppressed if deposition takes place within nanopores of a given substrate. Gomes et al. [131,132] state that by the addition of certain surfactants 1 it is possible to deposit zinc with a different preferred orientation, crystal shape (needles, pyramids, cauliflowers) and size. However, these solutions are impractical for application in a battery because they would either increase the costs of such a battery dramatically, or severely influence the overall behaviour of the battery. ...
To counter the effects of global climate change, attributed to the CO2 emissions resulting from burning fossil fuels for generating electricity and heat, global efforts are being made to achieve an energy transition. This includes that the share of energy generated using sustainable sources (e.g. solar, wind, hydro) should be increased, while the share of energy generated using fossil sources (e.g. natural gas, coal, oil) should be decreased, ultimately phasing out the usage of fossil fuels altogether. How this energy transition should be achieved, or even when the energy transition should be completed is subject of heated debates in political arenas, courts of law and the society as a whole. Whether or not future electricity demands can be met by sustainable sources is a particular important part of this debate. On the one hand, fossil fuels are (for the moment) cheap and readily available, by using fossil fuels it is always possible to generate the appropriate amount of electricity to match the demand. On the other hand, generating electricity from sunlight or wind can only be done when enough sunlight is available or the wind-speed is in an appropriate bandwidth. However, as electricity is also used during the night, and on cloudy, windless or stormy days, using sustainable energy sources as the primary supply for electricity generation can lead to a significant mis- match between supply and demand. This can imply that sometimes the electricity generated by solar parks during the day has to be curtailed because there is no demand for it, while during the night electricity still has to be generated using fossil fuels to meet the demand.
A solution to this problem seems obvious: store the electricity. This allows to generate electricity using sustainable sources when available, and to store a sufficient amount to be able to meet the demand at all times. Although, this solution sounds simple, still many questions remain. Which type of storage should be used?, Where should the storage be located?, What should be the capacity of the storage?, How should the storage be used?, etc. In this thesis these types of questions are addressed for a specific type of storage: batteries. To answer these questions, and to support the important decisions necessary to complete the energy transition, three contributions are made:
The first contribution is the development of the diffusion buffer model (DiBu-model) for battery state of charge (SoC) prediction. This model is specifically designed to be used in simulation tools for energy management in (smart) grids. Hence, this model should be a consolidation of broad applicability, accuracy and simplicity. The broad applicability of the DiBu-model is demonstrated by accurate predictions of the SoC of Lead-acid, Lithium-ion Polymer and Lithium Iron-phosphate batteries under various scenarios. The accuracy of the model is demonstrated by comparing the predicted SoC for various scenarios to the SoC calculated from measurements on real batteries subjected to these scenarios. The results show that it is possible to accurately predict the SoC for these types of batteries using the DiBu-model, where the difference between the predicted SoC and the SoC calculated from measurements is generally less than 5%.
The broad applicability and accuracy are also demonstrated by accurate SoC predictions on an experimental Seasalt battery, although a slight modification to the model was necessary in this case. The simplicity is demonstrated by integrating the DiBu-model in the DEMKit smart grid energy management toolkit. Here the results show that by using the DiBu-model more realistic predictions of the SoC can be made, compared to an idealized battery model used previously. The integration of the model in DEMKit is validated by comparing the SoC predicted using DEMKit to the SoC derived from measurements on an actual battery. The difference between the predicted and measured SoC is generally less than 1.5%.
The second contribution is the so called "16 houses case" in which the integration of batteries in a smart microgrid is considered. More specifically the possibilities of "soft-islanding" (near autarkic behaviour) a microgrid with 16 houses is investigated. The research is focussed on an idealized "greenfield" neighbourhood where energy is generated by PV-panels as well as by a CHP and energy is stored using batteries as well as a heat buffer. Firstly, a proper sizing of the equipment is determined based on energy production and consumption data of several weeks spread over the year. Secondly, one- year simulations for several scenarios are presented and the degree of autarky (DoA) for each scenario is compared. It is demonstrated that a (nearly) autarkic operating microgrid can be achieved by combining the proper sizing of energy generation and storage assets, with an advanced control. It is possible to achieve a DoA of 99.1% over a year, meaning that less than one percent of the energy has to be imported from the main grid. Subsequently the tools and methods used for the ideal neighbourhood are applied in a case study of a real neighbourhood: Markluiden. For this neighbourhood it is possible to reach a DoA of around 91% over a year.
The third contribution concerns the Seasalt battery, a novel battery currently under development at Dr Ten B.V. The Seasalt battery is particularly suitable for stationary use, e.g. as a home or neighbourhood battery. In that role it is an alternative to e.g. Lead-acid and Lithium-ion Polymer batteries. A detailed description of the battery and its behaviour is given, in addition to a discussion of its advantages and disadvantages. The advantages include the usage of environmentally friendly and (where possible) sustainable materials in its construction, and limited risks to health and safety compared to Lead-acid and Lithium-ion Polymer batteries. Disadvantages include a lower capacity
/ weight and capacity / volume ratio in comparison with the aforementioned batteries. Furthermore, examples of real-world application of the Seasalt battery are discussed. Finally, the prevention of dendrites forming at the anode of the Seasalt battery, which was a particularly challenging aspect of the battery design, is discussed in detail.
... morphologies of metal electrodeposit obtained from aqueous systems have been conventionally controlled by current density, cathodic overpotential, the composition of electrolytes, and additives. [28][29][30][33][34][35][36][37][38][39][40][41][42] The effect of the loss of free water on the morphologies is discussed in comparison to the conventional trends. Current density and/or cathodic overpotentials have been reported to vary the preferred orientations. ...
Concentrated aqueous solutions attract considerable attention because water electrolysis can be suppressed due to a decrease in the amount of free water. The present study focuses on electrodeposition behaviors of metallic zinc (Zn) using concentrated aqueous solutions containing bis(trifluoromethylsulfonyl)amide (Tf 2 N – ) anions. An increase in Tf 2 N – concentration significantly enhances water-anion interactions, giving characteristic infrared spectra for the breakdown of the hydrogen-bonding networks of water clusters, i . e . loss of free water. For the Tf 2 N – system Zn electrodeposits with the preferred orientation of hcp basal plane was observed, while, for the SO 4 2– system with the presence of the hydrogen-bonding networks, preferred orientation of basal plane was not observed. The preferred orientation of basal plane is not attributed to the adsorption of Tf 2 N – anions on the electrode, proved by the use of mixed Zn(Tf 2 N) 2 -ZnSO 4 concentrated solutions. The loss of free water in the concentrated Zn(Tf 2 N) 2 solutions will suppress hydrogen adsorption at the cathode to promote surface diffusion of intermediate Zn ⁺ adions and growth of Zn crystals. Consequently, the promotions and the easier growth of Zn basal planes with the lowest interfacial free energy will enhance the horizontal growth of Zn basal planes.
... Shitanda et al. [20] report that creating a dot-pattern on the substrate surface at the nanolevel yields dendrites only where the dots are located on the substrate surface, while Koda et al. [21] note that dendrite formation can be suppressed if deposition takes place within nanopores of a given substrate. Gomes et al. [22,23] state that by the addition of certain surfactants it is possible to deposit zinc with a different preferred orientation, crystal shape (needles, pyramids, cauliflowers) and size. However, these solutions are impractical for application in a battery because they would either increase the costs of such a battery dramatically, or severely influence the overall behaviour of the battery (e.i. the progression of voltage and current during charging and discharging, the Open Circuit Potential, etc.). ...
Dendrite formation poses serious problems in the operation of zinc-based batteries. Electrode material and electrolyte composition are known to have an influence on the dendrite formation. In this paper possible solutions for the reduction of dendrite formation at the anode of a zinc-based battery are studied. The electro-chemical behaviour of various electrode materials and electrolyte compositions is researched. It is observed that the tested electrode materials have no significant impact on the reaction at the anode. However, significant reduction in dendrite formation are observed at various electrode materials. The largest reduction in dendrite formation is observed when SGL bipolar graphite is used as electrode material. Furthermore, using several analysis methods (CV, EIS, SEM) it is observed that the addition of low concentrations (around 10% of the main component concentration) of certain additives (MgBr 2 , MnSO 4) to the electrolyte has no significant impact on the electrolyte reaction at the anode, but prevents the formation of dendrites. Finally, the changes in substrate material and electrolyte additive do not have significant influence on the overall performance of the battery.
... The relation between the cathodic peak current density and the square root of the scan rate (ν 1/2 ) is presented in Fig. 6. As can be seen in Fig. 6, the two plots of j p against v 1/2 are linear but do not pass from the origin, indicating that in addition to the diffusion-controlled process, Zn deposition is substantially controlled by the transfer process [39,40]. ...
A novel additive sodium diisopropylnaphthalene sulfonate (SDIPNS) was investigated in Zn-Mn electrodeposition on steel from chloride bath. To this end, cyclic voltammetry was performed in absence and presence of SDIPNS to study different electrochemical systems. Electrochemical data showed that SDIPNS increases Zn deposition overpotential, resulting from strong adsorption of SDIPNS molecules on the cathode surface. The effects of scan rate, switching potentials on the electrochemical behavior of Zn-Mn co-deposition were investigated. The variation of scan rate reveals that the Zn-Mn co-deposition is associated with charge transfer coupled with the mass transfer. SDIPNS concentration was investigated with regard to the Mn content in the final coatings. The chemical composition result showed that Mn-rich deposits, containing 20 wt.% of Mn, are successfully deposited under low cathodic potential (E = − 1.52 V vs. Ag/AgCl). The surface characterization of Zn-Mn coatings was explored by scanning electron microscopy (SEM). The presence of SDIPNS in the electrolytic bath permits to obtain compact, well adherent, and fined grain Mn-rich alloys.
... The influence of CTAB concentration on the orientation of crystal growth was further evaluated through XRD as shown in (201) planes, according to standard pattern (JCPDS card no. 00e004e0831) and these are in agreement with the literature (Gomes and da Silva Pereira, 2006a;Gomes and da Silva Pereira, 2006b;Nayana and Venkatesha, 2015). However, variations in the peak intensities represent the preferential orientation of the crystals. ...
The main objective of this study is to integrate two energy-intensive metallurgical processes, Cu extraction from CuFeS2 and Zn electrowinning, into a battery-like device that could incentivize renewable energy use at remote mining locations. In this device, Cu extraction and Zn electrowinning occur simultaneously during the charge cycle. During discharge, the device, referred to as a trifunctional battery (TFB), can supply back to an electrical circuit a portion of the stored energy. The re-dissolution of Zn during discharge and reversible reactions at a chalcopyrite slurry electrode are responsible for this energy release. The high initial specific energy (388 Wh–g⁻¹ at 0.5 C discharge rate) registered by this setup decreased to ≈50 Wh–g⁻¹ during the initial 15 galvanostatic charge ̸ discharge cycles and remained almost constant in the subsequent 85 cycles. The low coulombic (≈50%) and energy efficiencies (≈40%) demonstrated by the TFB occurred at maximum (23%) Cu extraction from CuFeS2. A feature of the TFB is that the normally unwanted irreversible reactions that occur in traditional batteries are in fact desirable in the TFB, i.e., they lead to valuable Cu extraction in addition to energy storage.
... Organic additives used in electroplating are known as inhibitors and prone to adsorb on cathode surface to rise overpotential. 63,64 Therefore, Ni 2+ -containing intermediates are expected to be obstructed in motions and surrounded by negatively charged benzene rings and thus promote nucleation and reduce island radius. 65,66 The absorbate usually promotes a 3D cluster growth mode upon polycrystalline growth. ...
High-density growth nanotwins enable high-strength and good ductility in metallic materials. However, twinning propensity is greatly reduced in metals with high stacking fault energy. Here we adopted a hybrid technique coupled with template-directed heteroepitaxial growth method to fabricate single-crystal-like, nanotwinned (nt) Ni with anomalously high-density nanoscale twins. The nt Ni primarily contains hierarchical twin structures that consist of coherent and incoherent twin boundary (CTB and ITB) segments with few conventional grain boundaries. In situ compression studies show the nt Ni has a high flow strength of ~ 2 GPa and good deformability. Moreover, the nt Ni offers superb corrosion behavior due to the unique twin structure in comparison to coarse grained and nanocrystalline counterparts. The hybrid technique opens the door for the fabrication of a wide variety of single-crystal-like nt metals with unique mechanical and chemical properties.
Metallic zinc is an excellent anode material for Zn-ion batteries, but the growth of Zn dendrite severely hinders its practical application. Herein, an efficient and economical cationic additive, poly dimethyl diallyl ammonium (PDDA) was reported, used in aqueous Zn-ion batteries electrolyte for stabilizing Zn anode. The growth of zinc dendrites can be significantly restrained by benefiting from the pronounced electrostatic shielding effect from PDDA on the Zn metal surface. Moreover, the PDDA is preferentially absorbed on Zn (002) plane, thus preventing unwanted side reactions on Zn anode. Owing to the introduction of a certain amount of PDDA additive into the common ZnSO4-based electrolyte, the cycle life of assembled Zn||Zn cells (1 mA·cm−2 and 1 mAh·cm−2) is prolonged to more than 1100 h. In response to the perforation issue of Zn electrodes caused by PDDA additives, the problem can be solved by combining foamy copper with zinc foil. For real application, Zn-ion hybrid supercapacitors and MnO2||Zn cells were assembled, which exhibited excellent cycling stability with PDDA additives. This work provides a new solution and perspective to cope with the dendrite growth problem of Zn anode.
This article covers zinc–bromine redox flow battery (ZBB) technology, which is a redox flow battery technology that is suitable for large‐scale energy storage. Due to its nonflammability, relatively high energy density, and modular design, the ZBB is now a promising candidate for energy storage systems on multi‐kW to MW scales. This article presents a thorough description of the electrochemical principle, major components, and structural design of ZBB. The information collected from a wide range of studies is organized in a new configuration to elicit the key features of ZBB technology and the issues involved in advanced ZBB technology.
The superhydrophobic photocatalytic self-cleaning coating has both physical and chemical self-cleaning properties, which has attracted wide attention of researchers in recent years. In this paper, ZnS superhydrophobic coating was prepared on the surface of zinc substrate by economic and environmental friendly solvothermal method and chemical modification method. By means of EDS, X-ray diffraction and X-ray photoelectron spectroscopy (XPS), it was proved that ZnS superhydrophobic coating was successfully formed on the surface of zinc substrate after solvothermal reaction and chemical modification. Moreover, the morphology of the coating surface was observed to be nanobeam by scanning electron microscopy, and the Cassie contact state was formed when water droplets contacted with the superhydrophobic coating surface containing ZnS nanobeam. In addition, the physical and chemical self-cleaning properties of ZnS superhydrophobic coatings were tested and their principles were explored. The results show that the nanobundle ZnS superhydrophobic coating has excellent physical and chemical self-cleaning properties.
Owing to the properties of cost‐efficient, high‐energy density and environmental friendliness, rechargeable aqueous zinc‐metal batteries (RAZMBs) are promising candidates for the next generation metal‐based batteries in large‐scale energy storage systems. However, the practical applications of RAZMBs are severely limited due to the presence of inevitable side reactions referring to zinc corrosion and hydrogen evolution reaction (HER) occurring at the electrode‐electrolyte interface. The uninterrupted interfacial side reactions at the expense of continuous capacity fading and reduced reversibility of zinc are required to give more attention to mitigate them. Given the above concerns, in this review, the fundamental principles of corrosion thermodynamics and kinetics of zinc electrodes in aqueous media are elucidated. Furthermore, the recent optimization strategies targeting enhanced stability of zinc electrodes are reviewed including electrolyte additives, zinc alloying, electrodeposited Zn and coating treatments. Finally, considering the current main research orientations, some perspectives are provided to facilitate the development of future applications of zinc anodes.
This work reports effects of supercritical carbon dioxide (SC-CO2) on the dispersion of TiO2 in Ni-TiO2 composite films prepared by SC-CO2 assisted co-electrodeposition. Pure Ni and Ni-TiO2 composite films prepared by the conventional electrodeposition method are prepared as comparisons. The average grain size of the Ni matrix is compared from the X-ray diffraction results, and grain refinement is observed in the composite film prepared by the SC-CO2 assisted co-electrodeposition. The incorporation amount of TiO2 and the dispersity in the composite film are determined from results obtained in energy dispersive X-ray mapping analysis, and the TiO2 content reaches 5.47 wt% and the dispersity of TiO2 becomes more uniform in the composite film by the SC-CO2 assisted co-electrodeposition. The dispersity is quantified through a convolution process. Vickers hardness of the composite film reaches 1167 Vickers Pyramid Number (HV0.1/15) because of the fine Ni grains, high TiO2 content and uniform TiO2 distribution.
The growing demand for safer electrical energy storage has stimulated the pursuit of alternative advanced batteries. Aqueous Zn ion batteries (ZIBs) are receiving increasing attention due to their high safety,...
Corrosion behavior, morphology and micro-texture of Zn coatings, electrodeposited from electrolyte bath without and with surfactants of different polarity, were investigated and correlated. Polarization resistance (Rp) value which is directly proportional to the corrosion resistance behavior, was determined from the electrochemical impedance spectroscopy technique. Rp value was highest for the coating with Cetyltrimethylammonium bromide [CTAB (cationic surfactant)], followed by coatings with Sodium lauryl sulphate [SLS (anionic surfactant)], and Triton X-100 (non-ionic surfactant) surfactant. Surfactant-free coating showed the lowest Rp value, indicating lowest corrosion resistance. Surfactant-free coating and coating with SLS showed large-sized columnar grains, whereas coatings with CTAB and Triton X-100 contained smaller-sized grains throughout the coating thickness. XRD and EBSD suggested low energy near basal micro-texture on the coating surface with SLS as surfactant. Whereas other coatings with CTAB and Triton X-100 showed higher energy micro-texture. SLS containing coatings and surfactant-free coatings exhibited higher percentage (greater than 60%) of high angle grain boundaries (HAGBs). Zn coatings with CTAB showed lower fraction of HAGBs followed by coatings with Triton X-100. With similar micro-texture and grain boundary constitutions, in coatings electrodeposited using CTAB and Triton X-100, higher corrosion resistance in the case of CTAB was due to more compact and relatively less defective surface morphology. Between the coatings, produced without surfactant and using SLS surfactant, both of which exhibited similar columnar grains and percentage of high angle grain boundaries, the higher corrosion resistance in the case of SLS surfactant coating was due to near basal micro-texture along coating growth direction and high fraction of low energy special boundaries (90°/211¯0 angle/axis pair).
We investigate the electrodeposition of zinc on steel substrates using pulsed methods from additive‐free electrolytes in an industrially scalable parallel plate flow cell. We demonstrate that variables such as peak current and duty cycle can be used to independently control the morphology and preferential texture of the crystalline structure, which is, in turn, desirable for a variety of applications. Specifically, we have observed a transition of the preferential (002) facets at low peak current density (or low duty cycle) to (101) preferring facets at higher peak current density (or high duty cycle) as determined by the analysis of texture coefficients. Further analysis using scanning electron microscopy reveals a transition from the conventional hexagonal‐shaped particles of zinc to needle‐shaped structures, accompanied by a change in average crystallite size from 33 to 19 nanometers, determined from X‐ray diffraction studies. The variation in morphology is also correlated to crystallographic textures through the analysis of texture coefficients and an understanding of crystallization mechanisms occurring during deposition. Collectively, these results demonstrate that the morphology and crystalline orientation of zinc can be easily manipulated through tuning of the pulse parameters without the use of complex and expensive additives that have been traditionally used to achieve similar effects.
Co-W thin films have been produced as organic compounds using “electro deposition” with tri-sodium citrate. Typically, Co-W alloys have a strong toughness. Its hardness has been observed in various current temperatures and pressures. Co-W film having a strong magnetic behavior at a relatively low temperature and subtly changed to a soft magnetic nature as the temperature is elevated to a higher point. It was tested using a vibrational Sample Magnetometer. Surface morphology was analyzed using “XRD and SEM” measurements.
Rechargeable aqueous zinc ion batteries (ZIBs) have manifested great potential as an alternative to traditional electrochemical energy-storage devices. However, challenges concerned with zinc metal anode, including zinc dendrite and side reactions, severely hinder the performance of rechargeable ZIBs. Therefore, a profound comprehension of these challenges is necessary for the exploration of high-performance zinc metal anodes. Instead of simply introducing the implementation methods to improve the performance of zinc metal anode, this review overviews and categorizes the strategies towards the challenges of zinc metal anode by their essential design principles from the perspective of electrochemical and chemical reaction. Besides, the prospects of zinc anode development are proposed as well. This contribution is intended to throw light upon a systematical understanding of the strategies and provide insights into the future development of highly reversible and stable zinc metal anode for ZIBs.
Advanced energy storage devices are gaining attention due to increased demand for portable electronics. In this work, stable aqueous dispersions of graphene, carbon nanotubes, and their mixtures are produced with the aid of the surfactant sodium dodecylbenzene sulfonate. The method of electrodeposition is employed for the fabrication of films on copper, using the respective dispersions. These specimens are exposed to radiation of a xenon lamp, and characterization of the electrode material is carried out by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, attenuated total reflectance–Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. All-solid-state symmetric supercapacitors are successfully fabricated with the use of a gel electrolyte and the respective electrodeposited films on the electrodes. The electrochemical performance of the supercapacitors is evaluated by different electrochemical methods including cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The all-solid-state supercapacitor with the best electrochemical properties is the symmetric supercapacitor from irradiated electrodeposited films of carbon nanotubes on copper with areal capacitance 78.8 μF/cm2, energy density 0.04 μW·h/cm2, and power density 63.03 μW/cm2. Due to the facile and toxic-free scale-up of the electrodeposited process and the aqueous dispersions based on the carbon nanomaterials, the developed all-solid-state supercapacitor is suitable for energy storage devices.
Homogeneous mesoporous Ni-rich Ni–Pt thin films with adjustable composition have been synthesised by one-step micelle-assisted electrodeposition. The films exhibit a face-centred cubic solid solution (single phase) and their magnetic and mechanical properties can be tuned by varying the alloy composition. In particular, the Curie temperature (TC) is shown to decrease with the Pt content and thin films with a TC close to room temperature (i.e. Ni58Pt42) and below can be produced. Hysteresis loops show a decrease of saturation magnetisation (Ms) and coercivity (Hc) with decreasing Ni content. A comparison of porous and dense films reveals significantly lower saturation magnetic field strength for porous films. Concerning mechanical properties, mainly two trends can be observed: a decrease of the Young's modulus of the nanoporous films with respect to dense films by 10% in average and a progressive increase of Young's modulus with the Ni content from 4.2 GPa to 5.7 GPa in both types of films. The tunability of properties and facility of synthesis make this alloy a promising material for microelectromechanical systems (MEMS).
In this study, Triton X-100 was used as the WS2 dispersion agent in the Au–Co cyanide electrolyte to deposit Au–Co/WS2 composite coatings. Probe sonication was applied to exfoliate the commercial WS2 powders to produce thinner and smaller WS2 flakes, which improved the stability of the WS2 particles in the electrolyte. According to the electrochemical analyses, the effects of adding Triton X-100 and WS2 particles to the electroplating process were investigated. Through material characterizations, WS2 particles were proved to be compounded into the Au–Co matrix and showed clearly {002} preferred orientation due to their flake structures. Tribological tests were performed under dry condition in 10⁻³ Pa vacuum against stainless steel 316L balls with diameters of 3 mm and a normal contact force of 2 N. The Au–Co/WS2 composite coatings that developed showed the minimum coefficient of friction and wear rate of 0.05 and 8 × 10⁻⁶ mm³/N·m, which are 5 times and 3 times lower than the Au–Co reference coating, respectively.
The world’s mounting demands for environmentally benign and efficient resource utilization have spurred investigations into intrinsically green and safe energy storage systems. As one of the most promising types of batteries, the Zn battery family, with a long research history in the human electrochemical power supply, has been revived and reevaluated in recent years. Although Zn anodes still lack mature and reliable solutions to support the satisfactory cyclability required for the current versatile applications, many new concepts with optimized Zn/Zn²⁺ redox processes have inspired new hopes for rechargeable Zn batteries. In this review, we present a critical overview of the latest advances that could have a pivotal role in addressing the bottlenecks (e.g., nonuniform deposition, parasitic side reactions) encountered with Zn anodes, especially at the electrolyte-electrode interface. The focus is on research activities towards electrolyte modulation, artificial interphase engineering, and electrode structure design. Moreover, challenges and perspectives of rechargeable Zn batteries for further development in electrochemical energy storage applications are discussed. The reviewed surface/interface issues also provide lessons for the research of other multivalent battery chemistries with low-efficiency plating and stripping of the metal.
Growth of zinc dendrites has been an obstacle on the way of commercialization of Zn rechargeable aqueous batteries and various methods have been proposed for prevention and/or inhibition of them. We test one of such modifications, electrodeposition of zinc anode with sodium dodecyl sulfate (SDS), in aqueous Zn//LiCl + ZnCl2//LiFePO4 system and results show better capacity retention in comparison with conventional zinc anode.
The preparation of a Zn–TiO2 composite film has been performed by pulsed electrodeposition, from acidic zinc sulphate solutions, on an Fe support. The influence of the bath pH and the presence of a cationic surfactant (CTAB) on the composites structural and morphological characteristics has been investigated. The characterization of the samples was made by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) and atomic force microscopy (AFM). The experimental data show that for the composites prepared at pH 2, the metallic matrix presents a (0 0 2) preferential orientation. At pH=4, the deposit loses the preferred c-axis orientation and in addition a higher content of TiO2 particles is obtained. The use of the surfactant modifies the shape of the metallic grains, but little effect is observed on the dispersion of the semiconductor particles.
Pulse electrodeposition was used to produce nanocrystalline zinc from an aqueous zinc chloride electrolyte with polyacrylamide
and thiourea as additives. The influence of additive concentration and pulse electrodeposition parameters, namely, current-on
time, current-off time, and peak current density on the grain size, surface morphology, and preferred orientation was investigated.
The grain size and surface morphology of zinc deposits were studied by scanning electron microscopy and field emission scanning
electron microscopy. The preferred orientation of zinc deposits was studied by X-ray diffraction. The optimum concentrations
of polyacrylamide and thiourea in the bath that give the finest grains were 0.7 and 0.05 g/L, respectively. At constant current-off
time and peak current density, the grain size decreased asymptotically with increasing current-on time. An increase in the
current-off time at constant current-on time and peak current density resulted in grain growth. A progressive decrease of
the grain size was observed with increasing peak current density at constant current-on and -off time. Nanocrystalline zinc
with an average grain size of 50 nm was obtained at a peak current density of
The crystal orientations developed were correlated to the variation in the cathode overpotential accompanied with changing
the electrodeposition parameters. A
preferred orientation was developed at low overpotential while higher overpotential developed a dual
orientation. © 2004 The Electrochemical Society. All rights reserved.
A model for cathodic leveling based on a diffusion‐adsorption‐reduction mechanism for the leveling agent was tested experimentally
by electrodepositing nickel into a semicircular groove in the presence of coumarin. The inhibition of nickel by coumarin was
measured on a rotating disk electrode, and kinetics for the reduction of coumarin and Langmuir adsorption coefficient were
obtained from polarization data. Satisfactory agreement was found between experimentally measured and simulated leveling for
groove depths on the order of the diffusion layer thickness or smaller.
The influence of several ethoxylated additives (ethyleneglycol and polyethyleneglycol polymers of different molecular weights) on the nucleation, growth mechanism and morphology of zinc electrodeposited from an acidic chloride bath is reported. The electrochemical study was carried out using cyclic voltammetry, inversion potential and chronoamperometric techniques. The dimensionless graphs model was applied to analyse the nucleation process and the results showed that the studied additives have a blocking effect on the electrodeposition of zinc. This effect occurs in the first stages of the nucleation process and is dependent on the molecular weight of the additive. Changes induced by the presence of additives in the morphology and grain size of the deposits were observed using SEM analysis. Results show that the presence of additives modifies the nucleation process and determines the final properties of the deposits.
The effects of sodium lauryl sulphate(SLS) in the presence and absence of antimony(iii) on the current efficiency, power consumption and polarization behaviour of zinc were determined. The surface morphologies and deposit crystallographic orientations were also evaluated. The results were compared with glue as the addition agent. The addition of sodium lauryl sulfate to the zinc sulfate solution increased current efficiency, reduced power consumption and improved the surface morphology. Maximum current efficiency and minimum power consumption were achieved on addition of 0.02mgdm–3 Sb with 1mgdm–3 sodium lauryl sulfate.
A theoretical analysis based on charge balance and steady state and transient mass-transfer considerations has been used to determine the practical range of parameters during reverse-pulse current plating. The analysis shows that small duty cycles <0.5, pulse periods in the range of 1 to 1000 ms and a dimensionless reverse-pulse current up to 2.0 define the practical regime during metal plating. This analysis has been applied to copper deposition, for which the practical domains of reverse-pulse current plating are derived, Copper is plated by reverse-pulse currents from CuSO4/H2SO4 solution at a rotating cylinder. The microstructure of the deposits obtained are interpreted in view of the pulse parameters and fluid hydrodynamics used.
The influence of benzylideneacetone (BDA) on the mechanism of zinc deposition and nucleation was studied by voltammetry, chronoamperometry and atomic force microscopy (AFM). The addition of BDA to the electrolyte solution partially inhibited (97%) the reduction of zinc at the potential E = –1.15 vs SCE/V, giving rise to an increase in the overpotential for the discharge of the metal ion. This leads to the existence of two reduction processes with different energies that involve the same species, ZnCl4
2-. Analysis of chronoamperograms obtained in the absence and presence of BDA indicates that distinct nucleation mechanisms are involved during the initial stages of Zn deposition. In the absence of BDA, the transients are consistent with the model of 3D diffusion-controlled nucleation. In the presence of BDA, the transients exhibit a more complex form involving two growth processes. The first process, which occurs at short times, is explained in terms of a combination of three simultaneous nucleation processes: 2D progressive, 2D instantaneous, and 3D progressive nucleation, each limited by the incorporation of adatoms. The second process, which occurs at longer times, involves the three processes that occur at short times in conjunction with a principal contribution from a diffusion-controlled 3D nucleation mechanism. AFM imaging shows that the morphology of the deposited zinc depends on the applied electrode potential.
Voltammetry, galvanostatic polarisation and permeation experiments were used to determine the origin of the hydrogen absorbed in a steel substrate during zinc plating. Two hypotheses could be proposed to explain the hydrogen embrittlement of steel. The first hypothesis was the absorption of hydrogen by the bare steel before formation of the first zinc crystallites. The second hypothesis was the trapping of hydrogen in the deposit during plating and subsequent diffusion of hydrogen in steel. The results show that hydrogen evolution on bare steel was retarded by a zinc Under Potential Deposition. During zinc plating, the hydrogen permeation current decreased progressively with thickening of the deposit, showing a slight barrier effect. After 24 min the permeation current was still 80% of the maximum, and it continued decreasing for 100 min. It is concluded that the barrier effect does not prevent hydrogen trapped in the deposit to diffuse through the steel substrate.
Using an electrolysis cell with separate compartments, the polarization and impedance of the zinc electrode have been investigated in highly acidic sulfate electrolytes. It is shown that (i) zinc deposition implies a multi-step mechanism and takes place when hydrogen evolution remains passivated on the deposit surface, and (ii) the presence of Ni2+ ions and/or H2O2 molecules in the electrolyte depassivates the reaction of hydrogen evolution and enhances the rate of zinc corrosion. The experimental results have been simulated on the basis of a reaction model in which hydrogen evolution on the oxidized adsorbates (ZnOad or ZnOHad) generated near the corrosion potential is clearly distinct from hydrogen evolution on the metal surface involving ZnHad, which inhibits zinc deposition. Then the passivation of hydrogen evolution is associated with the reduction of oxidized adsorbates. The progressive adsorption of Ni2+ ions competes with the formation of oxidized adsorbates to slow down the passivation process, thus widening the potential domain where hydrogen evolution predominates.
The energy of the boundary between crystal and melt is calculated in a quasi-chemical approximation taking into consideration the correlation in the substitution of lattice sites by the atoms and the atomic interaction anisotropy. The molecular roughness of the interface is determined. The influence of correlation and anisotropy on the crystal surface roughness is ascertained. The numerical analysis for bismuth permitted one to obtain some information about the atomic interaction in solid, liquid and different phases.The energy of different lattice sites planes of monocrystals was calculated using the broken bonds method and its angular relation defined. The calculations are carried out for relative surface energies of lattice site planes which make up the various angles with plane (0001) of Be, Hf, Ti, Zr, Mg, Co, Zn and Cd monocrystals. A comparison between theoretical calculations and experimental data is carried out.
A hydroxide oscillation model has been proposed to account for the observed nanolaminated structure in electrodeposited Zn and Zn-Co alloys produced under potentiostatic control. At a critical cathode potential the Zn deposition proceeds in a cyclically changing environment arising from the regular formation and decay of a zinc hydroxide layer near the cathode surface, which produces Zn-ZnO laminations in the deposits. Co was found to enrich at the Zn-ZnO interface. Such a model is supported by evidence obtained from electrochemical measurements and transmission electron microscopy observations, and this has given some insight into the anomalous behavior of Zn-Co deposition.
The long-term capacity–time dependence of sodium decyl- and sodium dodecyl sulfate were measured at the mercury∣electrolyte interface for 0.1 M Na2SO4 electrolyte in the temperature range from 20 to 50°C at the potential of maximal adsorption. All capacity–time dependences exhibited a slow increase of the capacity after a sudden decrease in the short-term range. The corresponding long-term time dependence of the degree of coverage can be well described theoretically with a first-order surface reaction in which surface micelles are formed from a condensed film of perpendicularly interdigitated adsorbed molecules. The temperature dependence of the ratio of final equilibrium capacity to initial minimal capacity can be explained by the formation of hemispherical surface micelles in the case of sodium decyl sulfate and sodium dodecyl sulfate for the whole temperature range. A generalized packing parameter was introduced which involves the increase or decrease of the mutual distance of the head groups as well as the tail groups (and consequently their effective surface area) due to electrolyte ions or other surfactants. A necessary extension of the present electrochemical adsorption theory is discussed.
The roles of two model additives, bis(3‐sulfopropyl) disulfide (SPS) and Janus Green B (JGB), in the deposition of copper
from an acid‐copper sulfate electrolyte containing polyethylene glycol (PEG) and
were studied by deposition on microprofiled electrodes, scanning electron microscopy (SEM), and transmission electron microscopy
(TEM). It was found that leveling occurs only when all four additives are present, suggesting that additive‐additive interactions
are important to the leveling mechanism. Moreover, an optimal flux of the active leveling agent exists, an effect that may
be explained by the classical diffusion‐adsorption theory of leveling. SEM and TEM micrographs show that the additive SPS
removes the columnar structure of the deposit and effects micron‐sized, unoriented grains provided PEG and
are present; the subsequent addition of JGB decreases the grain size of the film significantly. © 1999 The Electrochemical
Society. All rights reserved.
The electrochemical properties of N-tetradecyl-N′-methylviologen (TMV) in differently charged micelles were studied with a glassy carbon electrode using electrochemical techniques. The redox potential varied depending on the charge of the surrounding surfactants. When the viologen was situated in cationic micelles the redox potential for the 2+/1+ reaction was more positive than when situated in negatively charged micelles. The non-ionic micelles destabilised the 2+-state most showing the highest redox potentials. From studies of several different cationic micelles it was concluded that the most important parameter for the redox potential was the surface charge density. A calculation based on a simple model confirmed this. Other interactions also influenced the stability of the redox states. Adsorption, desorption and reorganisation of the surfactants at the electrode surface caused capacitive currents. To control the nonfaradaic current, differential pulse voltammetry (DPV) was used in addition to cyclic voltammetry.
The effects of some conventional additives such as triton X-10 (TX-10), sodium methylene bis(naphthalene sulfonate) (NNO), phenylbenzylketone (PBK), and a CH-1 brightener on the electrodeposition of zinc onto the glassy carbon electrode were examined using chronoamperometry. The surface morphology, grain size, and texture of the deposits were characterized by scanning electron microscope, transmission electron microscope, and X-ray diffraction. It was found that the electrocrystallization mechanisms of zinc and microstructure of deposits are sensitive to the identity of organic additives. On one hand, in the absence of additive or in the presence of NNO or PBK, zinc deposition proceeds by three-dimensional instantaneous nucleation and growth, while in the presence of TX-10 or a CH-1 brightener, zinc deposition follows the three-dimensional progressive nucleation and growth. On the other hand, in the absence of additive, the deposit forms a loose and porous structure with no texture. In the presence of PBK and TX-10, the deposits are (101) and (110) texture, respectively. And in the presence of a CH-1 brightener, deposit is smooth and bright and forms a (101) and (110) texture, where a homogeneous distribution of small 8 nm grains appears. These facts show that the effects of a CH-1 brightener on the zinc electrodeposition mainly result from the combinational action of TX-10 and PBK. In addition, we also found that surface morphology of deposits is strongly correlated to deposit texture.
Pulse electrodeposition exhibits marked advantages over direct current electrodeposition in the control of deposit grain size, surface morphology, and preferred orientation. The effect of pulse peak current density (Jp) on the grain size and surface morphology of zinc deposits with additives (polyacrylamide and thiourea) was studied by scanning electron microscopy and field emission scanning electron microscopy. The preferred orientation of zinc deposits was studied by X-ray diffraction, and microhardness of the deposits was measured by a Knoop microhardness tester. Increasing JP dramatically changed the surface morphology and decreased the grain size. Nanocrystalline zinc (56 nm) was produced at JP=2 A cm−2. At JP equal to 0.4 A cm−2, the preferred orientation of zinc deposits was and changed to the prismatic orientation at Jp equal to 0.8, 1.2, and 1.6 A cm−2. However, increasing the peak current density to 2 A cm−2 altered the prismatic to the random The microhardness increased to approximately 8 times higher than that of pure polycrystalline zinc (0.29 GPa). Microhardness reached a maximum (2.3 GPa) at 1.6 A cm−2, then decreased to 1.5 GPa at 2 A cm−2. The hardness drop was correlated with the presence of additives and the change in texture from to the random with increasing Jp.
The effects of the organic additives cetyltrimethylammonium bromide (CTABr) and tetrabutyl ammonium bromide (TBABr) on the electrowinning of zinc from acidic sulphate solutions were studied in the presence and absence of trace amounts of antimony(iii). The results indicated that CTABr has similar properties to the commonly used industrial additive glue with respect to current efficiency, power consumption, polarization behaviour, and the crystallographic orientation and surface morphology of the zinc deposits. TBABr was generally less useful with respect to all these properties. Voltammetric studies indicate that polarisation for zinc electrodeposition decreased in the order CTABr > glue > TBABr. The nature of the electrode reactions were investigated through measurements of exchange current densities, Tafel slopes and transfer coefficients.
Electrowinning of zinc from zinc chloride solutions, acidified by HCl, was conducted in a cation exchange membrane cell. The current efficiency was correlated with the deposit morphology. The deposits having lesser surface defects, which act as active sites for hydrogen adsorption, exhibited higher current efficiency. The (1 1 0) preferred texture was observed on the deposits grown in high acid solution containing gelatin. High temperature (40 C) and high current density decreased the current efficiency and the preferred texture.
The kinetics of zinc deposition from a concentrated chloride electrolyte containing a commercial additive are investigated by impedance spectroscopy. A reaction model formerly validated for zinc deposition in acidic sulphate medium has been adapted to the present electrolyte and closely related to the elementary steps involved in the crystal growth process. Simulation of the electrode kinetics shows that the additive modifies the deposit morphology by changing some specific rates of the surface steps: slowing down the charge transfer reactions, poisoning the active kink sites and increasing the deposition overpotential. Thus zinc deposition takes place on a surface where the intermediate adions Zn+
ad and the active kink sites are more numerous and where the nucleation rate is increased, leading to refined grain size.
The interaction of poly(ethylene glycol) M
n= 3000 with copper I and II ions in aqueous-acidic media was studied by investigation of the specific electrical conductivity, optical density and the cyclic voltamperometric curves in Cu+ and Cu2+ solutions. The results suggest the formation of complexes of the {Cu+(-EO-)3(x – 1)H2O} and {Cu2+(-EO-)4.(y – 1)(H2O)2} types. In the case when {–CH2CH2-O-}
n
and Cl– are simultaneously present in the copper electrolyte, the possibility of simultaneous complex formation between both copper ions and ethylene oxide units, and copper ions and chloride ions is considered. The strong increase in copper electrodeposition over-potential after the addition of polyethers to the electrolytes containing brighteners is explained by the formation of these complexes.
The influence of oxide surface charge on the corrosion performance of zinc metals was investigated. Oxidised zinc species (zinc oxide, zinc hydroxychloride, zinc hydroxysulfate and zinc hydroxycarbonate) with chemical compositions similar to those produced on zinc during atmospheric corrosion were formed as particles from aqueous solution, and as passive films deposited onto zinc powder, and rolled zinc, surfaces. Synthesized oxides were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and electron probe X-ray microanalysis. The zeta potentials of various oxide particles, as determined by microelectrophoresis, are reported as a function of pH. Particulates containing a majority of zinc hydroxycarbonate and zinc hydroxysulfate crystallites were found to possess a negative surface charge below pH 6, whilst zinc oxide–hydroxide and zinc hydroxychloride crystallites possessed isoelectric points (IEP’s) higher than pH 8. The ability of chloride species to pass through a bed of 3 μm diameter zinc powder was found to increase for surfaces possessing carboxy and sulfate surface species, suggesting that negatively charged surfaces can aid in the repulsion of chloride ions. Electrochemical analysis of the open-circuit potential as a function of time at a fixed pH of 6.5 showed that the chemical composition of passive films on zinc plates influenced the ability of chloride ions to access anodic sites for periods of approximately 1 h.
Square-wave cathodic current modulation was used to electrodeposit ultra-fine-grained nickel from an additive-free Watts bath. The influence of pulse parameters, namely, pulse on-time, off-time and peak current density on the grain size, surface morphology and crystal orientation was determined. The study showed that an increase in peak current density resulted in considerable refinement in crystal size of the deposit. The crystal orientation progressively changed from an almost random distribution at the lowest peak current density of 400 mA cm−2 to a strong (200) texture at a peak current density of 1600 mA cm−2. At constant peak current density and off-time, the crystal size of the deposit was found initially to decrease with pulse on-time before it started to increase with further increase in on-time. The crystal orientation progressively changed from an almost random distribution at the shortest on-time of 1 ms to a strong (200) fibre texture at an on-time of 8 ms. An increase in the pulse off-time at constant on-time and peak current density resulted in a progressive increase in crystal size. However, the crystal orientation remained unaffected with increasing off-time.
The texture development during iron electrodeposition was simulated using a Monte Carlo model presented in a companion paper [1]. The simulation illustrated that the surface-energy anisotropy played an important role in the formation of fibre texture, and that the texture changed with the current density, bath temperature and the pH value of the bath. It was demonstrated that the surface-energy anisotropy was influenced by the co-deposition of hydrogen, and this could be the reason responsible for the texture variation with the deposition condition. It was demonstrated also that when a magnetic field of sufficient strength was applied during the deposition process, the magnetocrystalline anisotropy induced a non-fibre texture, which gradually dominated the initially formed fibre texture as the deposit grew. Various electrodeposition experiments were performed to corroborate the Monte Carlo simulation. A positive correlation between the Monte Carlo simulation and the experiments was found.
This paper reviews recent advances in understanding electron transfer between electrodes and reactants in micellar solutions, and suggests molecular pictures for such events. Experimental findings clearly indicate the influence of surfactant aggregates at the electrode-fluid interface in micellar solutions. These aggregates may be arranged in bilayers, cylinders, or surface micelles depending on the nature of the electrode surface and the surfactant. Entry of an electrochemical reactant into this dynamic surface film is a key step preceding electron transfer. Micelle-bound reactant may dissociate, followed by entry of the reactant into the surface film. Alternatively, the micelle may deliver reactant by joining with surface aggregates. In both cases, the result is a mixed adsorbate layer of reactant and non-electroactive surfactant on the electrode prior to electron transfer. Depending on the reactant's ability to compete with non-electroactive surfactant for surface sites on the electrode, electron transfer can involve adsorbed reactant or reactant which approaches the electrode to within a distance roughly equivalent to the diameter of the surfactant head group.
The kinetics of anodic dissolution and corrosion of zinc coatings deposited onto steel sheet either by electrodeposition or by hot dipping are investigated by electrochemical impedance spectroscopy in aerated sulfate medium. The results are compared with those obtained previously on pure bulk zinc and interpreted on the basis of the model derived in the first part of this paper. It is shown that zinc coatings are less sensitive to corrosion than pure bulk zinc and changes of their behavior with time are not identical. Important differences are observed between the various coatings in the respective contributions of the three parallel paths of the dissolution process. Three kinds of oxidation products were identified by Raman spectroscopy. A compact non-stoichiometric zinc oxide was formed by surface reaction on zinc. Above it, a thick and porous layer made of zinc hydroxi-sulfate and stoichiometric ZnO, was formed by precipitation from a local saturation of the solution. A strong correlation was evidenced between the oxidation products and the various paths of the reaction model. It was assumed that the impurities, initially present in the metal, may affect the interfacial reactions, the increase of the micro-roughness, and may also reinforce the protective properties of oxidation product layers. The differences between the various zinc coating behaviors result mainly from their impurities. Their crystal preferred orientations have no significant influence.
The first stages of the zinc electrodeposition process on highly oriented pyrolytic graphite (HOPG) from a 0.1 M ZnSO4 + 0.5 M Na2SO4 solution were analyzed in the absence and in the presence of gelatine as additive, using cyclic voltammetry, potentiostatic current transients and atomic force microscopy. In the solution free of gelatine the zinc deposition can be interpreted by a model involving instantaneous nucleation on active sites and diffusion-controlled 3D growth. In the solution containing gelatine the HOPG surface is partially covered by a gelatine film which blocks the steps edges and surface defects, decreasing the nucleation rate and affecting the nucleation mechanism. The morphology of the Zn crystals formed would be also affected by the gelatine adsorption in the first stages of deposition.
Until recently, the rapid time scales associated with the formation of an adsorbed surfactant layer at the solid-aqueous interface has prevented accurate investigation of adsorption kinetics. This has led to the mechanism of surfactant adsorption being inferred from thermodynamic data. These explanations have been further hampered by a poor knowledge of the equilibrium adsorbed surfactant morphology, with the structure often misinterpreted as simple monolayers or bilayers, rather than the discrete surface aggregates that are present in many surfactant-substrate systems. This review aims to link accepted equilibrium data with more recent kinetic and structural information in order to describe the adsorption process for ionic surfactants. Traditional equilibrium data, such as adsorption isotherms obtained from depletion approaches, and the most popular methods by which these data are interpreted are examined. This is followed by a description of the evidence for discrete aggregation on the substrate, and the morphology of these aggregates. Information gained using techniques such as atomic force microscopy, fluorescence quenching and neutron reflectivity is then reviewed. With this knowledge, the kinetic data obtained from relatively new techniques with high temporal resolution, such as ellipsometry and optical reflectometry, are examined. On this basis the likely mechanisms of adsorption are proposed.
- H Yan
- J Dawnes
- P J Baden
- S J Harris
H. Yan, J. Dawnes, P.J. Baden, S.J. Harris, J. Electrochem. Soc. 143
(1996) 1577.
- M S Kh
- C C Youssef
- P S Koch
- Fedkiw
Kh. M.S. Youssef, C.C. Koch, P.S. Fedkiw, J. Electrochem. Soc. 151
(2004) 103.
- G Trejo
- H Ruiz
- R Ortega
- Y Borges
- Meas
G. Trejo, H. Ruiz, R. Ortega Borges, Y. Meas, J. Appl. Electrochem.
31 (2001) 685.
- A Gomes
- M H Mendonça
- M I Da Silva
- F M Pereira
- Costa
A. Gomes, M.H. Mendonça, M.I. da Silva Pereira, F.M. Costa, J.
Sol. Stat. Electrochem. 9 (2005) 190.
- Z A Matysina
- L M Chuprina
- S Yu
- Zaginoichenko
Z.A. Matysina, L.M. Chuprina, S.Yu. Zaginoichenko, J. Phys. Chem.
Solids 53 (1992) 167.
- A M El-Sherik
- U Erb
- J Page
A.M. El-Sherik, U. Erb, J. Page, Surf. Coat. Technol. 88 (1996) 70.
- Kh
- C C Saber
- P S Koch
- Fedkiw
Kh. Saber, C.C. Koch, P.S. Fedkiw, Mater. Sci. Eng. A 341 (2003)
174.
- U Retter
- M Tchachnikova
U. Retter, M. Tchachnikova, J. Electroanal. Chem. 550/551 (2003)
201.
- J F Rusling
J.F. Rusling, Coll. Surf. 123/124 (1997) 81.
- A Gomes
- M H Mendonça
- M I Da Silva Pereira
- F M Costa
A. Gomes, M.H. Mendonça, M.I. da Silva Pereira, F.M. Costa, J.
Sol. Stat. Electrochem. 9 (2005) 190.
- R Atkin
- V S J Craig
- E J Wanless
- S Biggs
R. Atkin, V.S.J. Craig, E.J. Wanless, S. Biggs, Adv. Coll. Interf. Sci.
103 (2003) 219.
- J Kostela
- M Elmgren
- P Hansson
- M Almgren
J. Kostela, M. Elmgren, P. Hansson, M. Almgren, J. Electroanal.
Chem. 536 (2002) 97.
- A E Alvarez
- D R Salinas
A.E. Alvarez, D.R. Salinas, J. Electroanal. Chem. 566 (2004)
393.
- C Madore
- D Landolt
C. Madore, D. Landolt, J. Electrochem. Soc. 143 (1996) 3936.