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 Ti 3 C 2 T x MXene, tellurium/Ti 3 C 2 T x (Te/Ti 3 C 2 T x ) 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/Ti 3 C 2 T x . The photo-R ZICs results exhibited a capacitance enhancement of 50.86% for Te/Ti 3 C 2 T x 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 Ti 3 C 2 T x at only a 5 mV s -1 scan rate. Furthermore, both samples achieved photo-charging voltage responses of ≈960 mV, and photoconversion efficiencies of 0.01% (for Te/ Ti 3 C 2 T x ) and 0.07% (for Ti 3 C 2 T x ). 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.