Enhanced super capacitance performance of V2O5•nH2O/g-C3N4 nanocomposites: Synthesis, characterizations, and electrochemical properties

The primary problem addressed in this study is to enhance the performance of supercapacitor electrode materials by developing a cost-effective, and efficient synthesis method for nanocomposites with high capacitance. Hence, in this study, we report the synthesis of V2O5 center dot nH2O/g-C3N4 nanocomposites using a cost-effective hydrothermal method, resulting in four distinct samples: pristine V2O5 center dot nH2O nanoribbons (VO) and three composites with varying amounts of g-C3N4 (10, 20, and 30 mg), labelled as VCN1, VCN2, and VCN3. Structural, morphological, optical, and electrochemical characterizations were conducted to assess their potential as supercapacitor electrode materials. Electrochemical analysis, including cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD), confirmed pseudocapacitance behavior in all samples. VCN1, containing 10 mg of g-C3N4 in V2O5 center dot nH2O matrix, exhibited the highest specific capacitance of 230 F/g at a scan rate of 10 mV/s in a 3 M KOH electrolyte. This enhancement in capacitance is attributed to the added g-C3N4, which increases active sites, as confirmed by Electrochemically Active Surface Area (EASA) measurements. Additionally, electrochemical impedance spectroscopy (EIS) supported VCN1's superior performance, identifying it as a promising, cost-effective electrode material for super capacitor applications.