Amorphous nitrogen-doped carbon layers forming the interfacial channel for rapid charge transfer in ZnIn2S4/BiVO4 Z-scheme photocatalyst for enhancing organic pollutants degradation with simultaneous hydrogen evolution

Abstract

Efficient photocatalytic hydrogen evolution from the organic wastewater represents an ideal solution for simultaneously addressing energy shortages and environmental pollution. However, the sluggish transport of photogenerated carriers at contact interface poses a key obstacle to enhancing photocatalytic activity. Here, ZnIn2S4/BiVO4@N-C (ZIS/BVO@N-C) Z-scheme photocatalysts were successfully constructed by a simple hydrothermal-impregnation method. ZIS/BVO@N-C-10% demonstrated outstanding photocatalytic performance, achieving a hydrogen evolution rate of 2695.68 μmol·g−1·h−1 and a degradation rate of 492.96 mmol·g−1·h−1 under visible light, surpassing those of ZIS (851.52 μmol·g−1·h−1 and 174.83 mmol·g−1·h−1) and ZIS/BVO-10% (1228.98 μmol·g−1·h−1 and 277.78 mmol·g−1·h−1). Characterization results and density functional theory (DFT) calculations revealed that the introduction of the N-C layer reduced interfacial impedance and enhanced the strength of interfacial electric field, overcoming the interfacial barrier and improving the photogenerated separation and migration efficiency at the interface, and ultimately enhancing the photocatalytic activity of ZIS/BVO@N-C. Based on experimental and characterization results, the photocatalytic mechanism of ZIS/BVO@N-C Z-scheme has been proposed. Furthermore, ZIS/BVO@N-C exhibited excellent stability, highlighting its potential for practical applications. This work also presents a new strategy for designing highly active Z-scheme photocatalysts for organic wastewater treatment and simultaneous hydrogen energy recovery.