Photoassisted Enhancement of Capacitance in the rGO-g-C3N4-ZnCo2O4 Heterojunction-Based Supercapacitor.

Abstract

The ever-increasing demand for renewable energy sources necessitates efficient methods for harvesting and storing clean energy. A photosupercapacitor is an energy storage device that shows improved charge storage performance in the presence of light, which is necessary to mitigate the current energy crisis. Here, we have presented rGO-g-C₃N₄-ZnCo₂O₄ as a photoelectrode for a photoassisted supercapacitor. Photoelectrode selection was based on the suitable relative energy level positions of each component. The sample was synthesized by hydrothermal and thermal exfoliation processes and characterized by XRD, SEM, DRS, and XPS. We have achieved a 25-30% enhancement in capacitance under illumination (1 Sun AM 1.5G). In addition, we have also analyzed diffusive and capacitive contributions exhibited by the sample in order to understand the charge storage mechanism. In order to analyze light-induced enhancement, PL and TRPL were conducted, which verify the transfer of photogenerated holes from g-C₃N₄ to ZnCo₂O₄. Hence, this work demonstrates a sustainable strategy for charge storage enhancement in next-generation energy storage devices.