Controllable Sulfur Vacancy Engineering and Lean-Liquid System for Enhanced Solar-Driven Hydrogen Evolution on Metal Sulfide Photocatalysts

Abstract

Bulk and surface defects are critical lattice imperfections in photocatalytic semiconductors, each playing distinct roles in charge dynamics. Intrinsic bulk defects typically serve as recombination centers for photo-generated electron-hole pairs, thereby impeding charge diffusion. In contrast, surface defects function as active sites for substrate adsorption and charge transfer, enhancing charge separation efficiency. However, surface defects often introduce localized deep impurity energy levels that trap electrons, reducing charge carrier lifetimes. To address these challenges, this study employs plasma chemical vapor deposition (PCVD) technology to controllably generate sulfur vacancies (Sv) on the surface of metal sulfides. Subsequently, a lean-liquid system is constructed to realize a localized thermal effect, facilitating efficient electron-hole pair separation at the defect level. By integrating these strategies, the optimized 10Sv/Cu0.04In0.25ZnSy@Ru (10Sv/CIZS@Ru) photocatalyst achieves a remarkable hydrogen evolution rate of 651 mmol·h-1·m-2 under visible light irradiation. This work provides a promising approach for designing efficient solar-driven photocatalysts for sustainable green hydrogen production.