Figure 3 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
(a) FT-IR and (b) Raman spectra of sample S120, polyaniline and graphene/polyaniline composites prepared by chemical polymerization.
Source publication
As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of s...
Contexts in source publication
Context 1
... As shown in Figs 2 and S3, PANi nanofibers with diameter of 50~100 nm and length of several micrometers are directly intercalated into GNS. Similar microstructures are observed by different hydrothermal temperature treat- ment. SEM images of the GNS/PANi nanofibers exhibit that PANi nanofibers are tightly and uniformly connected with GNS (Fig. S3). And also, many pores are observed in the SEM images. This microstructure may also greatly improve the electrochemical properties due to facile electrolyte diffusion and increase the ratio of active materials to attend the electrochemical ...
Context 2
... order to evaluate the structural stability of PANi treated or synthesized by hydrothermal process, we further characterized Fourier transformation infrared (FT-IR) and Raman spectrum of the GNS/PANi composites. As a control, PANi and GNS/PANi (PANi-120) synthesized by chemical polymerization has used as standard sample for comparison. As shown in Fig. 3a, the peak positions of all three samples are the same, indicating that the hydrothermal treatment did not affect the FTIR results, which indirectly proved that the PANi is stable at this moderate temperature. Further increasing the hydrother- mal temperature to 150 and 180 °C, the FTIR curves are also similar with the chemical ...
Context 3
... that all peaks can be assigned to the characteristic peaks of PANi, but slightly shifts are observed compared to the pure PANi by chemical polymerization. This may be caused by the structure changes of PANi in the direct hydrothermal process. The Raman spectra show no significant structural changes occurring during the hydrothermal treatment (Fig. 3b), except for the relative intensity of the peaks. The spectrum of neat PANi show bands at 1170, 1341, 1547 and 1620 cm −1 corresponding to C-H bending of the quinoid ring, C-N stretching of the bipolaron structure, N-H bending of the bipolaronic structure and C-C stretching of the benzenoid ring, respectively. Because the quinoid rings ...
Similar publications
Nitrogen-doped graphene quantum Dots (N-GQDs) are emerging electroactive and visible light active organic photocatalysts, known for their high stability, catalytic activity and biocompatibility. The edge surfaces of N-GQDs are highly active, however, when N-GQDs make the film the edges are not fully exposed for catalysis. To avoid this issue, the N...
Due to the abundant accessible pores for ion storage, hierarchical short diffusion paths for ion transport, and high diffusion efficiency through macropores, newly developed hierarchical porous carbons (HPCs) have been attracting much attention as one of the most promising electrode materials for high-performance supercapacitors. However, the large...
Herein, three-dimensional (3D) nitrogen-doped graphene with large surface areas and abundant porous structures was prepared by a hydrothermal synthesis method, which served as a novel support to enhance the catalytic properties of noble metal catalysts for the solvent-free selective oxidation of benzyl alcohol. The as-prepared samples were characte...
Citations
... Pyrolysis is the most commonly used technique for converting biomass into carbon materials at high temperatures without oxygen to produce porous carbon structures suitable for energy storage applications [52]. Hydrothermal carbonization is another critical technique for converting biomass into carbon at high temperatures and pressure in water, resulting in unique properties of carbon materials [53]. Template methods are also used to control the morphology and porosity of BDC materials, which involves sacrificing templates to form specific structuring in the synthesized materials [54]. ...
Modern research has made the search for high-performance, sustainable, and efficient energy storage technologies a main focus, especially in light of the growing environmental and energy-demanding issues. This review paper focuses on the pivotal role of biomass-derived carbon (BDC) materials in the development of high-performance metal-ion hybrid supercapacitors (MIHSCs), specifically targeting sodium (Na)-, potassium (K)-, aluminium (Al)-, and zinc (Zn)-ion-based systems. Due to their widespread availability, renewable nature, and exceptional physicochemical properties, BDC materials are ideal for supercapacitor electrodes, which perfectly balance environmental sustainability and technological advancement. This paper delves into the synthesis, functionalization, and structural engineering of advanced biomass-based carbon materials, highlighting the strategies to enhance their electrochemical performance. It elaborates on the unique characteristics of these carbons , such as high specific surface area, tuneable porosity, and heteroatom doping, which are pivotal in achieving superior capacitance, energy density, and cycling stability in Na-, K-, Al-, and Zn-ion hybrid supercapacitors. Furthermore, the compatibility of BDCs with metal-ion electrolytes and their role in facilitating ion transport and charge storage mechanisms are critically analysed. Novelty arises from a comprehensive comparison of these carbon materials across metal-ion systems, unveiling the synergistic effects of BDCs' structural attributes on the performance of each supercapacitor type. This review also casts light on the current challenges, such as scalability, cost-effectiveness, and performance consistency, offering insightful perspectives for future research. This review underscores the transformative potential of BDC materials in MIHSCs and paves the way for next-generation energy storage technologies that are both high-performing and ecologically friendly. It calls for continued innovation and interdisciplinary collaboration to explore these sustainable materials, thereby contributing to advancing green energy technologies.
... This, however, has drawbacks including cyclic stability and weaker electrochemical characteristics. The volumetric energy density of a composite hybrid with macropores in micropore size is not favorably influenced by the three-dimensional structure [280]. As a result, it is very difficult to create porous, ultrathin, and homogenous nanocomposite layers. ...
Polyaniline (PAni) is a widely studied conductive polymer that has unique properties such as high conductivity and stability. However, poor solubility and mechanical properties limit its prospective applications. To overcome these limitations, different synthesis methods have been developed and studied. One of these methods is to make the composites of PAni which displayed prominent results not only in addressing poor stability but also in achieving high mechanical properties. This review summarizes various synthesis methods, properties, and applications of PAni composites that have been incorporated with different materials such as carbon, carbon nanotube, graphite, graphene oxide, metal and metal oxides, metal–organic framework, bio-molecules, silica, and many more to enhance their potential applications. The most important applications of the PAni composite are briefly revealed at the end of this review and discussed appropriately.
... 20 Before now much research has been carried out using graphene to modify polymers to produce SC electrodes. 21,22 To achieve high specific capacitance of 532 to 305 F/g at scan rates of 2 to 50 mV/s, respectively, Wang et al. 23 hydrothermally created ultra-thin sheets similar to graphene nanosheet/PANI composites. Farid et al. 24 concurrently treated GO and PANI with thiol, revealing a porous structure with good dispersion and a large surface area. ...
Polyesters are renowned for their chemical resistance and thermal/mechanical properties but lack electrical conductivity. This study reinforces polyester with titanium and varying graphene (derived from rice husk ash [RHA]) percentages, testing resultant nanocomposites as supercapacitor electrodes. Transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction (XRD) confirm successful graphene synthesis from RHA, polymer crystallinity change and GN/Ti particle dispersion. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) assess nanocomposites, revealing enhanced properties with graphene. Suitability for supercapacitor electrodes increases proportionally with higher graphene percentages in CV tests. At a 20-mV/s scan rate, the specific capacitance for P–25 wt-%G sees an impressive 614% increase, underscoring significant enhancement in polyester matrix properties.
... The peaks at 1574 and 1487 cm À1 are attributed to the stretching vibrations of the quinone ring and benzenoid ring, respectively. 41,[58][59][60] Comparing the spectra, the main structure of PANI is not damaged after loading the metal oxides. The obvious blueshift is due to the interaction between PANI and the constituents of the formed metal oxides. ...
Photocatalytic CO2 reduction, as a highly integrated solar fuel generation technology, cannot efficiently utilize infrared light, resulting in a severe waste of solar energy. Given the fact that bifunctional polyaniline can conduct photocatalysis and promote water evaporation at the same time, integrating the advantages of a gas diffusion layer in mass transfer, we proposed a novel layout of the reacting system. In this constructed three-phase interface, polyaniline exhibited high activity for CO2 reduction, rather than hydrogen evolution. Through quasi-in situ Raman spectroscopy, we found that the introduced copper–cobalt composite oxides would be reduced to cuprous oxide/tricobalt tetroxide once photocatalysis starts. The highest achieved selectivity of ethanol-based C2+ products was >90%. The presence of a greater number of asymmetric adsorption sites between copper and cobalt facilitated C–C coupling, further proved by the density functional theory analysis. For water evaporation, the achieved energy conversion efficiency of solar to vapor was 71.0%. The evaporation was activated via the unabsorbed light by the photocatalyst and the unused light that had been absorbed. The vapor flux was driven across the hydrophobic gas diffusion layer into the flow in the backplate by the temperature gradient between each side of the gas diffusion layer. Subsequently, desalted water was obtained by condensation.
... The Raman spectra exhibit some defects, as indicated by the D band and a 2D band with an ID/IG ratio of < 1, indicating lower defects and improved aromatic structure [31,42]. The chemical exfoliation that takes place during the hydrothermal process may be the cause of these flaws [38]. As a result, the method enables the production of high-quality graphene on a large scale using low-cost methods. ...
The present work demonstrates a modified chemical synthesis route (chemical, hydrothermal methods, and sonication) for fabricating n-hexacosane-impregnated graphene nanosheets (GrPCM) nanocomposite, exhibiting enhanced thermal stability in energy storage. The exfoliation of the graphene sheet during the hydrothermal and sonication process increases the surface area that can absorb n-hexacosane, improving the impregnation and interaction between them. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy were used to examine the morphological and structural characteristics of the GrPCM nanocomposite. The findings demonstrate the loading of n-hexacosane PCM materials into porous nanosheet structures without any chemical reactions. Thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and infrared thermography (IR) were used to measure the latent heat, mass loss, thermal conductivity, and stability of as-synthesized GrPCM nanocomposites. The melting and solidification of GrPCM nanocomposite were observed at 57.11 ◦C with a latent heat of 154.61 J/g and 49.28 ◦C with a latent heat of 147.58 J/g, respectively. The GrPCM nanocomposites showed a thermal conductivity of 12.63 W/m K, which is enhanced compared to that of pure PCM materials of around 0.26 W/m K. Thermal performance measurements using infrared thermography revealed a significant increase in the nanocomposite's thermal conductivity over n-hexacosane, which was attributed to the reduced graphene nanosheet. Further, to study the heat transfer between fluid and different nanocomposites, the GrPCM nanocomposites were investigated inside a thermal storage tank. The experimental results were found in agreement with the COMSOL simulation and confirms GrPCM3 to be an excellent composite material for efficient heat transfer processes.
... As an oxidant, 25 mmol FeCl3.6H2O was added to the aforementioned solution (18,19). The prepared homogeneous solution and 4.0 × 5.0 cm 2 carbon felt electrode was added to the autoclave for hydrothermal synthesis for six h at 120 ⁰C (20). The electrodes were then rinsed in 1.0 M HCl solution and distilled water, then dried for 24 hours at 40 °C. ...
Polyaniline (PANI) is a promising conductive polymer for use in energy storage applications. Here, a one-step hydrothermal method of PANI polymerization on carbon felt electrode was synthesized using an azo dye, a bisulfonated dichloro anionic dye molecule to enhance an efficient textile-based flexible supercapacitor electrode material for energy storage applications. The electrode material synthesized at concentration of 2 mM AY17 exhibits 814.1 F g-1 at the scan rate of 5 mV s-1 with multiwall carbon nanotubes (MWCNTs). Due to electrostatic interaction with the polymer, the presence of high electronegativity Cl atoms in the dye molecule significantly improves the PANI structure's electron donor/acceptor properties. A symmetric supercapacitor exhibits an energy density of 11.7 W h kg−1 at a power density of 300 W kg−1, and it is 4.5 W h kg−1 at 1800 W kg−1 in 3.0 M KCl aqueous electrolyte. The capacitance retention performance value of the symmetric supercapacitor exhibited 81.76% after 2500 cycles.
... While, Aam had two major Raman bands between 3100-3400 cm −1 and 3400-3600 cm −1 attributed to the associated NH 2 (symmetric and asymmetric) and monomeric NH 2 (symmetric and asymmetric), respectively [47]. On the other hand, the Raman modes of Ca-Alg overlapped with PA at < 700 cm −1 and 950-1400 cm −1 and Si-O stretching between 950 and 1200 cm −1 [48,49]. The Raman D and G bands at 1350 and 1590 cm −1 are used to characterize the presence of GO and TRGO in the Alg-Aam-GO and Alg-Aam-TRGO hydrogels, respectively. ...
Natural gas can be sweetened by removing acidic gases with aqueous methyldiethanolamine (MDEA) solvents. Heavy metal ions and total organic acid anions (TOA) contaminate the industrial lean MDEA during this process. Continuous accumulation of these impurities creates operational problems, such as corrosion, fouling, and foaming of the operational unit. In this study, a series of interpenetrating network (IPN) nanocomposite hydrogels based on sodium alginate and acrylamide were successfully synthesized in the presence of fillers, such as silica (Alg-Aam-SiO2), polyaniline-coated silica (Alg-Aam-PA-SiO2), graphene oxide (Alg-Aam-GO), and thermally reduced graphene oxide (Alg-Aam-TRGO). The synthesized IPN hydrogels were applied for the adsorption of TOA and heavy metals (chromium and iron) simultaneously from lean MDEA. Different characterization techniques, such as FTIR, Raman, TGA, XRD, SEM, TEM, and equilibrium swelling studies, were performed to understand the superiority of the hydrogels. The maximum monolayer adsorption capacity of TOA anions at 53 °C was 21.45 mg/g for Alg-Aam, 23.47 mg/g for Alg-Aam-SiO2, 20.16 mg/g for Alg-Aam-PA-SiO2, 19.19 mg/g for Alg-Aam-TRGO, and 15.29 mg/g for Alg-Aam-GO. Thermodynamically, the adsorption of all contaminants was favorable, spontaneous, and endothermic. The produced Alg-Aam-based nanocomposite hydrogels are a great candidate for purifying the contaminated lean MDEA solvents.
... Methods to create these heterodoped materials include chemical vapour deposition, pyrolysis with a hetero precursor and self-doping [2]. Pseudocapacitance can also be added through polymer functionalisation, with polyaniline (PANI) being one of the most commonly used polymers [85][86][87][88][89][90][91][92]. ...
As worldwide energy consumption continues to increase, so too does the demand for
improved energy storage technologies. Supercapacitors are energy storage devices that are receiving
considerable interest due to their appealing features such as high power densities and much longer
cycle lives than batteries. As such, supercapacitors fill the gaps between conventional capacitors
and batteries, which are characterised by high power density and high energy density, respectively.
Carbon nanomaterials, such as graphene nanoplatelets, are being widely explored as supercapacitor
electrode materials due to their high surface area, low toxicity, and ability to tune properties for the
desired application. In this review, we first briefly introduce the theoretical background and basic
working principles of supercapacitors and then discuss the effects of electrode material selection
and structure of carbon nanomaterials on the performances of supercapacitors. Finally, we highlight
the recent advances of graphene nanoplatelets and how chemical functionalisation can affect and
improve their supercapacitor performance.
... The highest specific capacitance was found to be 810 F/g at 1 A/g for the RGO/PANI electrode with 20 wt% GO [85]. Wang at al. have shown that the specific capacitance of unmodified graphene nanosheets measured without and with PANI has more than five-fold difference from 102 F/g to 532 F/g at 2 mV/s, respectively [80]. Moreover, the cycling stability of such GNS-PANI composite was still as high as 99.6% after 1000 cycles at 50 mV/s or 94% after 2000 cycles. ...
The current development of clean and high efficiency energy sources such as solar or wind energy sources has to be supported by the design and fabrication of energy storage systems. Electrochemical capacitors (or supercapacitors (SCs)) are promising devices for energy storage thanks to their highly efficient power management and possible small size. However, in comparison to commercial batteries, SCs do not have very high energy densities that significantly limit their applications. The value of energy density directly depends on the capacitance of full SCs and their cell voltage. Thus, an increase of SCs electrode specific capacitance together with the use of the wide potential window electrolyte can result in high performance SCs. Conductive polymer polyaniline (PANI) as well as carbonaceous materials graphene (G) or reduced graphene oxide (RGO) have been widely studied for usage in electrodes of SCs. Although pristine PANI electrodes have shown low cycling stability and graphene sheets can have low specific capacitance due to agglomeration during their preparation without a spacer, their synergetic effect can lead to high electrochemical properties of G/PANI composites. This review points out the best results for G/PANI composite in comparison to that of pristine PANI or graphene (or RGO). Various factors, such as the ratio between graphene and PANI, oxidants, time, and the temperature of chemical oxidative polymerization, which have been determined to influence the morphology, capacitance, cycling stability, etc. of the composite electrode materials measured in three-electrode system are discussed. Consequently, we provide an in-depth summary on diverse promising approaches of significant breakthroughs in recent years and provide strategies to choose suitable electrodes based on PANI and graphene.
... Wang et al. followed an electrochemical polymerization approach to develop PANI as the active material for supercapacitors [48]. It was found a high electrical conductivity of 950 F/g at a current density of 1 A/g. ...
This study focuses on the synthesis of conductive polymers Polyaniline (PANI), Polypyrrole (PPy), Polythiophene (PTh), and Poly 3,4-Ethylenedioxythiophene (PEDOT) based copolymers, and their composites employing nano compound Titanium Oxide (TiO2) as well as their application in the fabrication of supercapacitors. All the samples in this study were synthesized by in situ chemical oxidative polymerization of aniline in the presence of additional monomers and composites. The co-polymer and nanocomposites were analyzed by FTIR, XRD, and Cyclic Voltammetry (CV). The electrochemical performance of the nanocomposites was measured using an electrochemical workstation (three-electrode system). The cyclic voltammetry exhibited that the addition of TiO2 in the Polyaniline backbones enhanced electrochemical characteristics. Cyclic voltammetry studies showed that at a scan rate of 10 mV/s, PANI/TiO2 had a specific capacitance of 494 F/g, whereas PANI-PPy/TiO2 composite had a specific capacitance of 457 F/g. In the case of the co-polymer set, PANI-PPy and PANI-PTh exhibited capacitance of 420 F/g and 415 F/g respectively whereas PANI-PEDOT copolymer showed lower specific capacitance of 366 F/g at 10 mV/s. Among all the nanocomposites PANI-PTh showed the highest capacitance retention of 98.9% after 100 cycles of charging and discharging compared to that of PANI-PPy (97.8%), PANI-PEDOT (96.6%), PANI/TiO2 (93.8%) and PANI (58.8%). Based on these electrochemical results, a conventional supercapacitor was successfully constructed with the nanocomposite serving as the negative electrode and activated carbon serving as the positive electrode.
