Construction of direct Z-scheme system for enhanced visible light photocatalytic activity based on ZnCdS/FeWO heterojunction.

A novel direct Z-scheme ZnCdS/FeWO (ZCS/FW) photocatalyst was prepared by a facile calcination method. The photocatalytic performance was investigated by photodegradation rhodamine B (RhB) and photocatalytic production hydrogen (H) under visible light irradiation. Compared with the pure ZCS, the ZCS/FW composites show considerably improved photocatalytic activity for degradation RhB and production H. Noticeably, the ZCS/FW with 7 wt% of FW exhibits optimal photocatalytic activity with the H evolution rate of 34.6 mmol g h and photodegradation of about 98% of RhB solution (10 mg l) in 60 min. These outstanding photocatalytic performances were found to be ascribed to the formation of direct Z-scheme heterojunction, resulting in effective separation and transfer of photogenerated charge carriers. Moreover, active species trapping experiments further demonstrate the electrons transfer followed Z-scheme system, and the photocatalytic mechanism was proposed.