Preparation of 3D porous g-C₃N₄@V₂O₅ composite electrode via simple calcination and chemical precipitation for supercapacitors

The unique three-dimensional (3D) porous structure of graphite carbon nitride (g-C₃N₄) and vanadium pentoxide (V₂O₅) was prepared by an environmentally friendly one-step solvothermal method, and its electrochemical performance was assessed. Importantly, g-C₃N₄ is a low cost material with excellent chemical stability, and it supports the vertical charge transfer during the charge-discharge process, which promotes electronic transmission along this direction. In addition, V₂O₅ has good theoretical capacitance and is deemed as a potential electrode material for next-generation supercapacitors. Field emission scanning electron microscopy of the nanocomposite revealed a 3D porous morphology for g-C₃N₄ (3D PCN) and a spherical morphology for V₂O₅. This study estimated the viability of the graphite carbon nitride-based nanocomposite PCN@V₂O₅ as a new catalyst in the supercapacitor (SC) anodes. A series of SC anodes with different catalyst loadings were produced. The electrochemical behavior of the SC anodes was calculated by cyclic voltammetry (CV), charge-discharge and cycling test. When test in electrochemical performance, the ratio of PCN:V₂O₅ is lower than 1:1 and 3D PCN@V₂O₅ exhibits a lower specific capacity, the ratio of PCN:V₂O₅ is higher than 1:1 that most of the pores in 3D porous g-C₃N₄ are covered that reduces the electron transport rate and results in a lower specific capacity. Overall, 3D PCN@V₂O₅ has higher specific capacity (457 Fg^-1 at 0.5 Ag^-1) and better cycling performance (approximately 84% after 500 cycles). This attractive performance indicates that 3D PCN@V₂O₅ could be used as potential electrode materials for supercapacitors.