In situ construction of all-solid-state Z-scheme g-C3N4/ZnNCN/ZnO with carbodiimide bridges for superior photocatalytic H2O2 production

Abstract

Photocatalytic production of Hydrogen peroxide (H2O2) via g-C3N4 represents an ideal solar-to-chemical conversion process, yet its efficiency is severely constrained by sluggish charge separation kinetics. Here, this bottleneck is overcome by constructing a novel ZnO/ZnNCN/g-C3N4 (ZZC) heterojunction, where the ZnNCN interlayer acts as an electronic bridge to mediate a robust all-solid-state Z-scheme system. This deliberately designed configuration facilitates an unprecedented spatial separation of charge carriers, effectively suppressing recombination and prolonging carrier lifetime. The resulting ZZC catalyst exhibits a superior photocatalytic H2O2 evolution rate of 0.81 mmol g−1 h−1, a 3.29-fold increase compared to pristine g-C3N4, marking one of the most efficient g-C3N4-based systems reported to date. Furthermore, this architecture endows the catalyst with excellent performance in the photodegradation of rhodamine B (RhB) and tereacycline. By introducing carbodiimide-bridged Z-scheme heterojunctions, this study provides a versatile strategy for designing next-generation photocatalysts for both energy synthesis and pollution control.