Fabrication of the SnS2/ZnIn2S4 heterojunction for highly efficient visible light photocatalytic H2 evolution

Abstract

A series of SnS 2 /ZnIn 2 S 4 ( x -SS/ZIS) photocatalysts with different mass ratios of SnS 2 were prepared by a hydrothermal method. The resulted composites were used for photocatalytic hydrogen evolution under visible light excitation. All the SS/ZIS composites exhibited significantly enhanced photocatalytic activity for H 2 evolution. Obviously, the highest H 2 evolution rate of 769 μmol g −1 h −1 was observed over 2.5-SS/ZIS, which was approximately 10.5 times that of the ZnIn 2 S 4 (73 μmol g −1 h −1 ). The enhanced photocatalytic performance was attributed to the successful construction of SnS 2 /ZnIn 2 S 4 heterojunctions, leading to rapid charge separation and fast transfer of the photo-generated electrons and holes under light irradiation. On the basis of PL, electrochemical impedance spectroscopy (EIS), photocurrent measurements and the H 2 evolution tests, a plausible photocatalytic mechanism was proposed. • SnS 2 /ZnIn 2 S 4 composites were synthesized from SnS 2 nanosheets and ZnIn 2 S 4 microspheres. • SnS 2 /ZnIn 2 S 4 heterojunctions enhanced photocatalytic H 2 production under visible light. • Efficient charge separation and transfer at the heterojunctions explained the improved performance.