Fig 4-
SEM images of the polyaniline electropolymerized in the pores of alumina template from solution of a) 0.1M aniline + 0.5M H 2 SO 4 by potentiostatic method; b) 0.1M aniline + 0.75M H 2 SO 4 by cyclic voltammetry at high magnification; c) 0.1M aniline + 1M H 2 SO 4 by potentiostatic method.
Source publication
An anodic aluminum oxide template-based process was adopted to fabricate polyaniline (PANI) nanotubes using the electropolymerization process. In addition, copper nanowires were synthesized into the PANI nanotubes by the "second-order-template" method. Cyclic voltammetry, potentiostatic and galvanostatic methods were performed for the fabrication o...
Contexts in source publication
Context 1
... growth of the polyaniline upon cycling is reflected from the increase in current response as well as due to the well-defined peaks at 0.2 and 0.48 V, which are due to the oxidation of polyaniline formed on the electrode surface. SEM images of the polyaniline synthesized from solution of 0.1 M monomer in 0.5 M H 2 SO 4 in the pores of the commercial alumina template of 200 nm in diameter are presented in figure 4 as a function of the electrolyte concentration and the polymerization method, after the template removal. It can be seen clearly the formation of nanotubes in figure 4b. ...
Context 2
... images of the polyaniline synthesized from solution of 0.1 M monomer in 0.5 M H 2 SO 4 in the pores of the commercial alumina template of 200 nm in diameter are presented in figure 4 as a function of the electrolyte concentration and the polymerization method, after the template removal. It can be seen clearly the formation of nanotubes in figure 4b. The nanotubes surface in figure 4a is very smooth with homogenous diameter. ...
Context 3
... the H 2 SO 4 concentration increases, it induces a more open morphology. The integrity of the nanotubes as the H 2 SO 4 increases is slightly poorer due to the hydrolysis, which is confirmed by the broken pieces observed in the images in figure 4c. Further, the template-based deposition of the copper nanowires into the polyaniline nanotubes was studied. ...
Citations
... The former is problematic because with increasing potential, not only is the monomer oxidized, but the pre-existing polymer can also be overoxidized. It is known that this can start at around 1.1 V [12,29], thus deteriorating the electrical properties of the polymer [30][31][32]. ...
Organometallic halide perovskites have emerged in the last decade as promising light absorbers for solar cell development. These devices require functional layers for both generated hole and electron extraction and transport. Among the hole transporting materials (HTM), poly(3,4-ethylenedioxythiophene) poly-(styrenesulfonate) or PEDOT:PSS layers have been widely obtained from a colloidal suspension. As an alternative, PEDOT:PSS can also be electrochemically deposited, allowing for synthesis control and performance design. In this study, the effect of the electrodeposition method of PEDOT on its HTM properties and solar cell efficiency was evaluated. The result showed a decrease in the HTM charge carrier density with the increase in the polymerization potential. When this potential is around 1.5 V (vs Ag/AgCl), the Raman spectra suggest the formation of side groups in the polymer chains resulting from over-oxidation. HTMs with a high charge carrier density increased the short-circuit current density (Jsc) and fill factor (FF) but reduced the open-circuit potential (Voc) of the solar cells. To avoid overoxidation, low synthesis potentials were applied. With this strategy, a 15.0% power conversion efficiency (PCE) was achieved using the galvanostatic method at 0.1 mA cm⁻², where the applied potential was ∼1 V. Consequently, this work paves the way for the optimization of the solar cell by simply controlling the electrodeposition potential of the PEDOT as HTM.
... The template method includes hard physical template method and soft chemical template method. Hard templates include porous alumina [60,61], halloysite [62,63], manganese oxide [64,65], etc. The hard template method can control the length, structure, diameter and arrangement of PANI fibers, but the template needs to be removed by post-treatment. ...
Polyaniline (PANI), as a representative of conductive polymers, has been widely used in anti-corrosion coatings. However, polyaniline has some disadvantages, such as poor dispersion, poor mechanical properties, conductive deactivation and even accelerating metal corrosion, which limit the further application of PANI in anticorrosion industry. This article summarizes the setbacks encountered in the study of polyaniline coatings and proposes improved methods respectively, and provides suggestions for further research on polyaniline in the future. Meanwhile, polyaniline composites have outstanding performance in the fields of smart coatings, super-hydrophobic coatings, antibacterial coatings, electromagnetic interference shielding coatings, and fire-resistant coatings in the past two decades. Herein, we summarize the research ideas, preparation methods and corresponding optimization measures of coatings in different fields, and provide guidance for the further application of polyaniline in anti-corrosion coatings.
... Anti-corrosive coatings based on electrochemically synthesized polymers have been investigated in the past years and their applicability for protection of mild steel substrate and other metals was reported [8][9][10][11]. Moreover, electrodeposition is a low cost method and it allows tailoring the properties of obtained structures by adequately controlling the growth parameters [12][13][14]. Being indicated for large area and high throughput production, electrodeposition is considered to be suitable for an industrial use [15][16][17]. ...
The nanostructured conducting polyanilines was synthesized using single and composite structure directing agents such as sodium dodecyl sulphate, sodium dodecyl benzene sulphonate, camphor sulphonic acid by chemical method. The effects of nature and concentration of structure directing agents (both single and composite) on pH characteristics, redox behaviour and solvent pattern were investigated using UV-Vis spectroscopy, Transmission electron microscopy, Cyclic voltammetry and Dynamic light scattering. Both concentration and nature of structure directing agents could influence the pH behaviour and workable pH range. The transition from conducting state to insulating state of all nanostructured conducting polyanilines occurred at higher pH than bulk PANI. The Transmission electron microscopy and Dynamic light scattering results showed that the morphology and the dimension of nanostructured conducting polyanilines at the doped and undoped state depended on the nature of structure directing agents used for polymerization. The redox properties were independent of nature and concentration of structure directing agents but electrochemical activity and solution behaviour of nanostructured conducting polyanilines depended on the nature of structure directing agents.
Homopolymerization of 3, 4-ethylene dioxythiophene (PEDOT) and copolymerization with N,N-dimethyl aniline (PDMA) were performed onto a platinum electrode. The synthesis was performed using potentiodynamic electrodeposition modes from LiClO4 solution containing 1:1 monomer ratio, in case of copolymer. The influence of sodium dodecyl sulphate (SDS) as a wetting agent was studied. The resulting copolymer films were characterised using cyclic voltammetry and EIS measurements in neutral phosphate buffer solutions. The results confirmed the obtainment of a new material by copolymerizing 3,4-ethylene dioxythiophene with N,Ndimethyl aniline with different properties than the corresponding homopolymers. SEM measurements showed that SDS surfactant had a marked influence on the films porosity. The specific capacitance of the PEDOT-PDMA copolymer was calculated and it showed good stability during cycling in PBS solution.
Electropolymerization and characterization of polyortophenylediamine (PODA) film and composite films of poly (o-phenylediamine) with functionalized single-wall carbon nanotubes (POPD/SWCNTS) and different additives were studied. These nanoporous composite films were grown electrochemically from aqueous solutions such that constituents were deposited simultaneously onto substrate electrode. The synthetic, morphological and electrical properties of obtained nanocomposite films were compared. SEM revealed that the composite films consisted of nanoporous networks of single-wall carbon nanotubes coated with polymeric film. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that these composite films had similar electrochemical response rates to pure polymeric films but a lower resistance and much improved mechanical integrity. The negatively charged functionalized carbon nanotubes served as anionic dopant during the electropolymerisation to synthesize polymer/functionalised carbon nanotube composite films. Using these composite films, the modified electrodes with improved properties were obtained.
Single-crystal ZnO nanowires long up to several microns were fabricated by one-step electrochemical deposition. A template-based process employing track-etched polycarbonate (TE-PC) membranes was used for this purpose. The morphology and the structure characteristics of the ZnO nanowires were analyzed by means of Scanning Electron Microscopy (SEM), Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), and Selected Area Electron Diffraction (SAED). The growth process conditions turned out to have a marked influence on the crystal nature and morphology of the nanowires. Deposition rates ranging from 0.4 nm s(-1) and up to 0.6 nm s(-1) were recorded for the growth of ZnO nanowires. The obtained results showed that by using carefully controlled deposition conditions single crystalline nanowires and fine-grained structures can be routinely obtained.
Surface studies are reported for the deposition of ZnO nanostructures by one-step electrodeposition method. The electrosynthesis was perfomed at the surface of tin doped indium oxide coated glass substrates in the absence of any buffer layer. The growth of ZnO nanostructures was investigated with the morphology of substrate and the deposition mode. Combined nucleation mode was observed for the ZnO independently of substrate. The results indicated the growth, morphology and density of the ZnO nanostructures are markedly influenced by both the substrate and the deposition conditions. It was observed the ZnO formation is defect site driven in case of galvanostatic deposition mode, while in case of potentiostatic deposition mode, it is dependent on the roughness of the substrate.
Nanoporous composite films of single–walled carbon nanotubes (SWCNTs) and polyaniline, were grown electrochemically from aqueous solutions such that constituents were deposited simultaneously onto substrate electrodes. Scanning electron microscopy (SEM) revealed that the composite films consisted of nanoporous networks of SWCNTs coated with polymeric film. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that these composite films had similar electrochemical response rates to pure polymeric films but a lower resistance and much improved mechanical integrity. The negatively charged functionalized carbon nanotubes (CNTsF) served as anionic dopant during the electropolymerization to synthesize polymer/CNTsF composite films. The specific electrochemical capacitance of the composite films is a significantly greater value than that for pure polymer films prepared similarly. Using these composite films, the modified electrodes with improved properties were obtained.
The polypyrrole/titania/polyaniline (PPy/TiO2/PANI) coaxial nanotube hybrid has been prepared through a stepwise electrodeposition process for an electrochemical energy storage. Independent TiO2 nanotube array was used as the framework, which was formed by anodizing titanium foil at 30 V in fluoride-containing water and ethylene glycol mixture solution. The PPy was selectively coated on the outer surface of TiO2 nanotube walls to form PPy/TiO2 through a normal pulse voltammetry electrodeposition process. The PANI was then coated on the inner surface of TiO2 nanotube walls to form PPy/TiO2/PANI coaxial nanotube hybrid through a photoassisted cyclic voltammetry electrodeposition process. The morphology and microstructure feature of PPy/TiO2/PANI were characterized by field-emission scanning electron microscopy and Raman spectrum. The capacitance performance was conducted by cyclic voltammetry and galvanostatic charge–discharge measurements. PPy/TiO2/PANI coaxial nanotube hybrid with P/N-type doping properties exhibited a high specific capacitance of 497 F g−1 at a current density of 0.5 A g−1 and a potential window of −0.2 to 0.8 V in 1.0 M H2SO4 solution. The capacitance declined from 267.9 to 193.7 F g−1 after 500 cycles at a high current density of 2.0 A g−1, showing 72.3% capacitance retention and a good cycle stability for the promising supercapacitor application.
