Nitrogen-Doped Carbon-Coated CuO-In2O3 p-n Heterojunction for Remarkable Photocatalytic Hydrogen Evolution

CuO as a catalyst has shown promising application prospects in photocatalytic splitting of water into hydrogen (H-2). However, the instability of CuO in amine aqueous solution limits the applications of CuO-based photocatalysts in the photocatalytic H-2 evolution. In this work, a novel dodecahedral nitrogen (N)-doped carbon (C) coated CuO-In2O3 p-n heterojunction (DNCPH) is designed and synthesized by directly pyrolyzing benzimidazole-modified dodecahedral Cu/In-based metal-organic frameworks, showing long-term stability in triethanolamine (TEOA) aqueous solution and excellent photocatalytic H-2 production efficiency. The improved stability of DNCPH in TEOA solution is ascribed to the alleviation of electron deficiency in CuO by forming the p-n heterojunction and the protection with coated N-doped C layer. Based on detailed theoretical calculations and experimental studies, it is found that the improved separation efficiency of photogenerated electron/hole pairs and the mediated adsorption behavior (| increment G(H)(*)|-> 0) by coupling N-doped C layer with CuO-In2O3 p-n heterojunction lead to the excellent photocatalytic H-2 production efficiency of DNCPH. This work provides a feasible strategy for effectively applying CuO-based photocatalysts in photocatalytic H-2 production.