WS2/In2S3 composite photocatalyst for photocatalytic H2 generation and pollutant degradation

Abstract

The recombination of photocarriers is a crucial factor that affects the performance of photocatalysts. Rationally designing the architecture of heterojunction photocatalysts is an effective strategy to inhibit the recombination through boosting photocarrier separation and transport. Herein, a Z-scheme WS₂/In₂S₃ photocatalyst with a bi-layered sheet-like structure was synthesized and investigated by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance, and Mott–Schottky measurements. The characterization results demonstrated that the unique architecture can reduce the charge transfer distance and provide more surface area to promote the photocatalytic reaction. Moreover, the Z-scheme structure effectively separates photocarriers while retaining their strong redox capability. Thus, a remarkable photocatalytic activity for H₂ generation and tetracycline hydrochloride degradation has been achieved. The results showed that the optimal 50 wt% Z-scheme WS₂/In₂S₃ composite exhibited the highest H₂ generation rate of 592.9 μmol g⁻¹ h⁻¹, and the best tetracycline hydrochloride degradation efficiency of 90% within 60 min. In addition, the bi-layered Z-scheme photocatalyst also exhibited excellent stability and recyclability. This work provides a new idea to promote the separation and transfer of photocarriers by building Z-scheme composite photocatalysts with appropriate nano building blocks, like nanosheets.