Beyond photocatalysis: “micro proton-battery-like” mechanism in V2O5/g-C3N4/Ti3C2 triads enables light-independent environmental remediation

Solar-driven photocatalysis is inherently limited by its diurnal discontinuity. Herein, we report a V 2 O 5 /g-C 3 N 4 /Ti 3 C 2 triadic composite that transcends this limitation via a “micro proton-battery-like” mechanism, enabling round-the-clock catalytic activity. The optimized composite achieves 93.9 % tetracycline degradation under visible light and, remarkably, maintains 64.1 % efficiency in the dark. This is underpinned by an 8-fold higher electron storage capacity (0.16 μmol/mg) than pristine g-C 3 N 4 , achieved via reversible V 5+ /V 4+ redox transitions. DFT calculations corroborate charge localization in V 3d orbitals during the light-driven “charging” phase and subsequent Ti 3 C 2 -mediated electron release for ·O 2 − generation in the dark. This work establishes a groundbreaking paradigm that unifies photocatalysis with electrochemical energy storage for persistent environmental remediation.