Morphology, structure and photocatalytic performance of ZnIn₂S₄ synthesized via a solvothermal/hydrothermal route in different solvents

Hexagonal ZnIn₂S₄ photocatalysts with different morphology and crystallinity (micro-structures) were prepared in aqueous-, methanol- and ethylene glycol-mediated conditions via a solvothermal/hydrothermal method. The aqueous- and methanol-mediated ZnIn₂S₄ presented to be Flowering-Cherry-like microsphere, while the ethylene glycol-mediated ZnIn₂S₄ presented to be micro-cluster. In comparison with two other products, aqueous-mediated ZnIn₂S₄ possessed the best crystallinity (micro-structure), which resulted in the highest photocatalytic activity for hydrogen evolution under visible-light irradiation. Additionally, aqueous-mediated ZnIn₂S₄ was found to be more stable than the other two ZnIn₂S₄ photocatalysts while undergoing the photocatalytic process. During the photocatalytic reaction, the average rates for hydrogen production over aqueous-, methanol- and ethylene glycol-mediated ZnIn₂S₄ were determined to be 27.3, 12.4 and 9.1 μmol h^-1, respectively, in the present photocatalytic systems.