In-situ formation of Ag/CuXO nanoarrays with an enhanced photo-response for photo-assisted supercapacitors

ABSTRACT The development of photo-assisted supercapacitors (PSCs) presents a significant opportunity to enhance energy storage capacity through the utilization of solar energy. A critical factor in this advancement is the creation of photoelectrodes that integrate high-efficiency light absorption, rapid charge separation, and substantial electrochemical activity. In this study, we successfully fabricated a bifunctional electrode by in situ growth of silver-loaded Cu X O nanoarrays (CF@Ag/Cu X O) on conductive copper foam. The Schottky junction formed between Ag and Cu X O significantly enhances the built-in electric field, thereby promoting the separation and transport of photo-generated charges while minimizing electron-hole recombination. This synergy improves both the light absorption capacity and photocurrent generation rate of electrode. Under illumination, the specific capacitance of this electrode at a current density of 10 mA·cm -2 increased from 945 to 1323 mF·cm -2 , reflecting an enhancement of approximately 40%. Additionally, it exhibited low charge transfer resistance, rapid kinetic behavior, and excellent cycling stability, with Coulombic efficiency remaining near 100% after 10,000 cycles under both dark and illuminated conditions. These findings clearly indicate that Ag loading effectively facilitates light-induced charge separation and reduces recombination, thus enabling the efficient conversion of light energy into electrochemical energy and providing a viable strategy for the design of high-performance photoelectrodes.