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Zinc vanadate (Zn3V2O8) rods have been prepared using easy and economical hydrothermal technique and are explored for supercapacitor electrode application. X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM) were analysed for the structure and morphology of the sample. The electrochemical performance of the Zn3V2O8 electrode was investigated using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge test. The performance of Zn3V2O8 in water soluble electrolytes, such as K2SO4, Na2SO4 and KOH were analysed, and the results demonstrated unique double layer properties of the material. The electrode material tested in 0.5 M K2SO4 showed good supercapacitive performance in terms of specific capacitance and efficiency when compared to other electrolytes. We have obtained a specific capacitance of 213 F g−1 at current density of 1 A g−1. This electrode exhibits very less charge transfer resistance (3.3 Ω) in potassium sulphate electrolyte and is lower than other electrolytes. Moreover, Zn3V2O8 provided enhanced rate capacity, with (77%) of retention capacity for charge–discharge up to 1000 cycles. [ABSTRACT FROM AUTHOR]

To accomplish superior performance in supercapacitors, a fresh class of electrode materials with advantageous structures is essential. Owing to its rich electrochemical activity, vanadium oxides are considered to be an attractive electrode material for energy storing devices. In this work, vanadium pentoxide (V2O nanostructures were prepared using surfactant (CTAB)-assisted hydrothermal route. Stacked V2O5 sheets enable additional channels for electrolyte ion intercalation. These stacked V2O5 nanosheets show highest specific capacitance of 466Fg at 0.5Ag. In addition, it exhibits good rate capacity, lower value of charge transfer resistance and good stability when used as an electrode material for supercapacitors. Further, an asymmetric supercapacitor device was assembled utilizing the stacked V2O5 sheets and activated carbon as electrodes. The electrochemical features of the device are also discussed. [ABSTRACT FROM AUTHOR]

A simple approach was adapted to synthesis nanoplatelet, nano urchin-flower and nanosphere NiMoO 4 by employing cetyl trimethyl ammonium bromide (CTAB) as a capping agent. Product pseudocapacitive property was studied by measuring suitable parameters. SEM studies revealed diverse morphology of NiMoO 4 nanoplatelet, nano urchin-flower and nanosphere within nanoscale region. Electrochemical studies explored the better electrode behavior of NiMoO 4 nanoplatelet (RC1) with specific capacitance of 178 F/g at 10 mV/s scan rate and 110 F/g at 100 mV/s scan rate. A Nyquist spectrum of products (RC1, RC2 and RC3) also revealed the better pseudocapacitive performance of NiMoO 4 . [ABSTRACT FROM AUTHOR]

CuMn 2 O 4 nanoparticles were successfully synthesized by adopting solvothermal method with optimum hydrothermal processing temperature maintained at 160 °C for 12 h. The synthesized CuMn 2 O 4 nanoparticles structure, morphology, optical and electrochemical properties were analyzed with respect to varying the hydrothermal temperature. The product dominant XRD peak observed at 35.8° matches well with corresponding planes of standard data. The IR vibrational modes of Mn-O and Cu-O band were authenticated by the peak appearance at 526 and 630 cm −1 . The rice-like morphology formation of CuMn 2 O 4 nanoparticles prepared at 160 °C hydrothermal processing temperature revealed the superior behavior of electrochemical properties. The electrochemical studies carried out to estimate the specific capacitance of CuMn 2 O 4 nanoparticles (MX3) at low scan rate 10 mV/s showed an excellent specific capacitance value of 520.4 F/g. The GCD studies of synthesized rice-like morphology CuMn 2 O 4 nanoparticles (MX3) revealed superior specific capacitance of 577.9 F g −1 at 0.5 A g −1 and retain its 98% capacitance as 571.6 F g −1 at 1 A g −1 current density. [ABSTRACT FROM AUTHOR]

MnMoO4 nanoparticles were synthesized by employing solvothermal method at optimized experimental condition to explore their electrochemical properties. The fundamental characterization studies such as X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectra confirmed the formation of pure phase of monoclinic crystal structure with C2/m space group. X-ray photoelectron spectroscopy studies revealed that the core-level Mn-2p spectrum peaks observed at 641.2 eV can be attributed to Mn-2p3/2 and that at 654.1 eV can be indexed to the binding energy of Mn-2p5/2. Major infrared peaks observed at 725, 800, 867, and 946 cm−1 could be designated to the characteristics bands of tetrahedral MoO4 groups in MnMoO4 nanoparticles. Raman peaks observed at 351, 823, 886, and 932 cm−1 corresponded to characteristics bands for MnMoO4 nanoparticles. The cyclic voltammetry studies at different scan rates (i.e., 10, 20, 30, 50, 80, and 100 mV s−1) were performed for all three MnMoO4 nanoparticles and displayed similar redox peaks in the positive and negative current regions, reflecting the pseudocapacitive nature. From galvanostatic charge-discharge profiles, it was found that MnMoO4 nanorods (R2) show high- capacitance of 697.4 F g−1 at 0.5 A g−1 current density and 40% increment in specific capacitance than other nanoparticles and can be considered as suitable nanomaterials as electrode for energy storage applications. [ABSTRACT FROM AUTHOR]

Carbon based electrocatalysts are promising candidates to achieve the production of hydrogen energy in a sustainable wayby simple water splitting technique. Thermally treated reduced graphene oxide (RGO) and N–S doped RGO employing urea and thiourea as electrocatalysts for hydrogen evolution reaction (HER). The performance of electrochemical HER has been thoroughly examined via linear sweep voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Furthermore, the Raman I D /I G ratio of RGO, N-RGO and NS-RGO were found to be 1.43, 1.10 and 1.11 respectively. From electrochemical HER analysis, we found that the NS-doped RGO exposed the low overpotential, low Tafel slope and low solution resistance value of 211 mV, 197 mV/dec and 0.34 Ω respectively. In addition, the chronoamperometry study revealed, the electrocatalyst NS-RGO showed an excellent stability (81.3% retention) with low 211 mV and remained unchanged for more than 16 h. Therefore, this work concludes that heteroatom dopant participate in improving electrocatalytic HER action. [Display omitted] • RGO, N-RGO, N–S-RGO were synthesized using hummer's and thermal treatment. • Interconnected sheets with numerous grooves and crumples were displayed. • I D /I G of RGO, N-RGO and NS-RGO were 1.43, 1.10 and 1.11. • NS-RGO exhibited an excellent stability (81.3% retention) with low 211 mV. • NS-RGO stability was unchanged over 16 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • Kaolin/g-C 3 N 4 /WO 3 nanocomposite has been synthesised and characterised. • The ternary nanocomposite has been characterized by various analytical techniques. • The specific surface area of the nanocomposite is obtained using BET isotherm. • The energy storage application of the nanocomposite has been studied using electrochemical, impedance and GCD studies. In order to investigate the synergistic potential of a new nanocomposite for improved energy storage applications, this work combines graphitic carbon nitride (g-C 3 N 4), vanadium pentoxide (V 2 O 5) and kaolin. Kaolin functions as a structural matrix, offering stability and support for the integration of g-C 3 N 4 and V 2 O 5 nanoparticles. It is well-known for its wide availability and thermal characteristics. A variety of analytical methods, such as electrochemical analysis, scanning electron microscopy and X-ray diffraction, are used to characterise the synthesised nanocomposite. The specific capacitance and cycling stability of the nanocomposite's electrochemical performance are rigorously assessed. Key issues in efficiency, stability and cost-effectiveness are addressed by an optimised material for advanced energy storage systems, which is the result of the synergistic effects coming from the unique features of each component. With a superior cyclic stability and capacitance retention of 77.7 % even after 2000 cycles, the composite material exhibits a higher specific capacitance value of 415 Fg−1 at 5 mVs−1. This work is a major step towards the creation of novel nanocomposites for high-performing, environmentally friendly energy storage systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antimony revealed rhombohedral crystal structure formation with D 3 d 5 (R 3 ¯ m) space group situated on symmetry C 3v sites. • In-plane longitudinal vibration (110.67 cm−1; E g) and out of plane vibration (A 1g ; 147 cm−1) revealed pure antimony. • The solution resistance value of Sb-NMP is 1.67 Ω and good conductive in nature. • Pure Sb (1.96 Ω) and Sb-Ball (1.93 Ω) exhibited low solution resistance value. • Sb-NMP showed exceptional HER performance with high stability of 80% retention. Modern research focuses exclusively on the search for relatively inexpensive, highly efficient electrocatalytic materials for the electrocatalytic hydrogen production water splitting reactions. Antimony is a chemical element having four allotropes with three oxidation states. Antimony is a semi-metal with elemental antimony. Recently, elemental antimony (Sb) with an extensive light absorption was recognized as good electrocatalytic for hydrogen evolution reactions. This study focuses on preparation and characterization of antimony nanoparticles for hydrogen evolution activities as explored. We report the structural, optical, vibrational, electrochemical properties of the pristine antimony nanoparticles for efficient catalytic material for electrochemical water splitting applications. The prepared antimony nanoparticles revealed the rhombohedral crystal structure formation with D 3 d 5 (R 3 ¯ m) space group situated on symmetry C 3v sites. In Raman studies, the peak appeared at 110.67 cm−1 corresponds to in-plane longitudinal vibration (E g) and at 147 cm−1 for out of plane vibration (A 1g) for pure antimony. The synergic effect of NMP and ultrasonication yields highly homogeneous antimony nanoparticles as evidenced from morphological analysis. From electrochemical impedance analysis, the solution resistance value of Sb-NMP is 1.67 Ω, which was small in comparison to the pure Sb (1.96 Ω) and Sb-Ball (1.93 Ω) and exhibited the good conductive nature of Sb-NMP nanomaterials. From electrochemical HER analysis, we found that the Sb-NMP showed the low 246 mV@10 mA/cm2 overpotential with low 186 mV/dec Tafel slope value. Furthermore, the chronoamperometry study exposed that the electrocatalyst Sb-NMP delivered an exceptional HER performance with high stability of 80% retention for continuous three hours measurements. Therefore, this study may perhaps facilitate the growth of antimony nanoparticles which can be used as an HER catalysts for improving the electrocatalytic HER activity. [ABSTRACT FROM AUTHOR]