Heterogeneous Structures Consisting of Rod‐like ZnO Interspersed with Ce2S3 Nanoparticles for Photo‐Sensitive Supercapacitors with Enhanced Capacitive Performance

Abstract

AbstractPhotosensitive supercapacitors incorporate light‐sensitive materials on capacitive electrodes, enabling solar energy conversion and storage in one device. In this study, heterogeneous structures of rod‐shaped ZnO decorated with Ce2S3 nanoparticles on nickel foam (ZnO@Ce2S3/NF) are synthesized using a two‐step hydrothermal method as photosensitive supercapacitor electrodes for capacitance enhancement under visible light. The formation of ZnO@Ce2S3 heterogeneous structures is confirmed using various structural characterization techniques. The area‐specific capacitance of the ZnO@Ce2S3/NF composite electrode increased from 1738.1 to 1844.0 mF cm−2 after illumination under a current density of 5 mA cm−2, which is 2.4 and 2.8 times higher than that of ZnO and Ce2S3 electrodes under similar conditions, respectively, indicating the remarkable light‐induced capacitance enhancement performance. The ZnO@Ce2S3/NF electrode also exhibits a higher photocurrent and photovoltage than the two single electrodes, demonstrating its excellent photosensitivity. The improved capacitance performance and photosensitivity under illumination are attributed to the well‐constructed energy‐level structure, which stimulates the flow of photogenerated electrons from the outer circuit and the involvement of photogenerated holes in the resulting surface‐controlled capacitance. In addition, the assembled ZnO@Ce2S3/NF‐based hybrid supercapacitor exhibits a great energy density of 145.0 mWh cm−2 under illumination. This study provides a novel strategy for the development of high‐performance solar energy conversion/storage devices.