Microwave-derived Fe2O3/rGO electrodes for photo-assisted supercapacitors with enhanced charge storage

Abstract

Designing semiconductor electrodes with efficient photogenerated charge separation is an effective strategy for improving the performance of photo-assisted supercapacitors and maximizing solar-energy utilization. Here, we report a microwave-assisted route for the synthesis of an Fe₂O₃/rGO composite as a photo-responsive pseudocapacitive electrode. Compared with pristine Fe₂O₃, the Fe₂O₃/rGO composite exhibits a slightly more negative conduction-band edge, which is favorable for electron excitation and interfacial charge transfer. In addition, the incorporation of rGO narrows the band gap, enhances light absorption, and promotes the generation and transport of photogenerated charge carriers. As a result, when used as an electrode for photo-assisted supercapacitive discharge, Fe₂O₃/rGO delivers a 19% increase in capacitance under illumination. This work provides a practical strategy for designing semiconductor/carbon composite electrodes for photo-assisted energy storage and offers insights into the development of high-performance solar-rechargeable energy-storage devices.