Z-scheme heterojunction enhanced photocatalytic performance for CO 2 reduction to CH 4 .

Due to the high charge separation efficiency leading to high photocatalytic activity, there has been significant interest in enhancing the charge separation ability of photocatalysts by controlling the heterojunction structure. To investigate the effect of the heterojunction structure on the photocatalytic performance of composite catalysts and understand its corresponding mechanism, a Z-scheme ZnFe 2 O 4 /ZnO/CdS heterojunction was constructed using the ultrasound method and used for CO 2 photoreduction. The Z-scheme heterojunction catalyst demonstrates elevated photocatalytic and charge separation efficiencies. Specifically, the conversion rate for the photocatalytic conversion of CO 2 to CH 4 reaches 105.9 μmol g -1 h -1 , surpassing that of the majority of previously reported semiconductor photocatalysts like ZnFe 2 O 4 /CdS. This research offers a fresh perspective on the development of innovative heterojunction photocatalysts and broadens the utilization of ternary composite materials in CO 2 photoreduction.