Step-scheme WO3/CdIn2S4 hybrid system with high visible light activity for tetracycline hydrochloride photodegradation

Photocatalytic degradation is an ideal choice for the treatment of antibiotic contaminant in water environment because of the characters of environmental-benign and sustainable. In this work, the visible-light-driven WO3/CdIn2S4 hybrid photocatalysts with different WO3 content were successfully fabricated by hydrothermal method. The phase structure, surface composition, optical properties, specific surface areas and charge separation were systematically by a series of measurements. The photocatalytic activity of resultant WO3/CdIn2S4 hybrid photocatalysts was evaluated by photocatalytic degradation for removal of tetracycline hydrochloride (TCH) and the results reveal that optimized photocatalytic efficiency in WO3/CdIn2S4 hybrid photocatalysts can be achieved by modulating the weight ratio of WO3 to CdIn2S4. The 70 wt% WO3/CdIn2S4 hybrid photocatalyst exhibited the best photodegradation activity. Significant enhancement of photocatalytic activity in WO3/CdIn2S4 hybrid photocatalysts is ascribed to effective charge separation due to the construction of step-scheme heterojunction. The photocatalytic mechanism involving charge transfer and separation, and degradation path using step-scheme WO3/CdIn2S4 hybrid photocatalysts were in-depth investigated and discussed. It is anticipated that our current investigation could open an avenue for design and preparation of step-scheme hybrid photocatalysts for environmental remediation.