Efficient photocatalytic H₂ evolution and Cr(VI) reduction under visible light using a novel Z-scheme SnIn₄S₈/CeO₂...

Semiconductor photocatalysis technology is a promising method for hydrogen production and water pollution treatment. Here, the SnIn₄S₈/CeO₂ (SISC) composites were fabricated by a stirring and calcination method, and the mass ratio of SnIn₄S₈ to CeO₂ was optimized. The 50 wt% SISC heterojunction photocatalyst has the highest visible light catalytic activity. The degradation rate of hexavalent chromium (Cr (VI)) is 98.8% in 75 min of light irradiation, which is 2.48 times that of pure CeO₂. Besides, the 50 wt% SISC composite photocatalyst also has the highest photocatalytic hydrogen production efficiency (0.6193 mmol g^-1 h^-1), which exhibits a higher photocatalytic activity than pure CeO₂ and SnIn₄S₈. The enhanced photocatalytic performance can be attributed to the Z-scheme heterojunction structure between CeO₂ and SnIn₄S₈, which can effectively separate and transfer photo-generated charges, thereby reducing the recombination of photo-generated carriers. We hope this work can provide ideas for constructing Z-scheme heterojunction structures and improving photocatalytic activity under visible light.