Rapid microwave preparation of CuS/ZnCdS Z-scheme heterojunction for efficient photocatalytic hydrogen evolution

Low-cost transition metal sulfides have been shown to be ideal candidates for photocatalytic hydrogen evolution. However, most preparation processes have long reaction times and high energy consumption. In this work, CuS/ ZnCdS heterojunction was prepared by a rapid and energy-saving microwave method. It was characterized by SEM, TEM, XRD, XPS, and photoelectrochemical tests. The results showed that CuS was successfully loaded with ZnCdS and did not alter the intrinsic structure of ZnCdS. It not only improved the light absorption efficiency, but lowered the position of the conduction band and reduced the forbidden band width. The optimum photocatalytic hydrogen evolution rate of CuS/ZnCdS could get 7.58 mmol g-1 h-1 and the AQE was 10.07% at 420 nm. The enhanced photocatalytic activity can be attributed to the construction of Z-scheme heterojunction to promote the separation and transfer of photogenerated charges. This work provides a valuable route to explore high quality ZnCdS based photocatalysts using a fast, low-cost microwave technique.