Powering the Future: Unleashing the Potential of MXene-Based Dual-Functional Photoactive Cathodes in Photo-Rechargeable Zinc-Ion Capacitor

Dual-functional photo-rechargeable (photo-R) energy storage devices, which acquire stored energy from solar energy harvesting, are being developed to battle the current energy crisis. In this study, these findings on the photo-driven characteristics of MXene-based photocathodes in photo-R zinc-ion capacitors (ZICs) are presented. Along with the pristine Ti3C2Tx MXene, tellurium/Ti3C2Tx (Te/Ti3C2Tx) hybrid nanostructure is synthesized via facile chemical vapor transport technique to examine them for photocathodes in ZICs. Interestingly, the evaluated self-powered photodetector devices using MXene-based samples revealed a pyro-phototronic behavior introduced into the samples, with higher desirability observed in Te/Ti3C2Tx. The photo-R ZICs results exhibited a capacitance enhancement of 50.86% for Te/Ti3C2Tx at two scan rates of 5 and 10 mV s-1 under illumination, compared to dark conditions. In contrast, a capacitance enhancement of 30.20% is obtained for the pristine Ti3C2Tx at only a 5 mV s-1 scan rate. Furthermore, both samples achieved photo-charging voltage responses of approximate to 960 mV, and photoconversion efficiencies of 0.01% (for Te/ Ti3C2Tx) and 0.07% (for Ti3C2Tx). These characteristics in MXene-based single photo-R ZICs are significant and considerable with the distinguished integrated photo-R supercapacitors with solar cells, or coupled energy-harvesting and energy-storing devices reported recently in the literature. The photoactivity of MXene-based dual-functional cathodes is considerable with the current integrated photo-rechargeable energy storage devices with solar cells. The newly advanced photo-rechargeable energy storage systems which couple photovoltaic and energy storage capabilities simultaneously, can improve energy storage and prevent the loss of energy transmission between discrete modules. This also simplifies the overall configuration and reduces package volume.image