CdS Nanorods and ZnCd-PBA Construct a Direct S-Scheme Heterojunction for Efficient Photocatalytic Hydrogen Evolution

The design of an S-scheme heterojunction can promote the transfer of photogenerated electrons, which is an effective method to improve the activity of photocatalytic hydrogen production. In this work, CdS/ZnCd-PBA composite catalysts were prepared by a simple physical method, and a CdS/ZnCd-PBA S-scheme heterojunction was designed. The close contact between the interface of the two catalysts is conducive to the rapid transfer of photogenerated carriers, providing a new path for electron transfer. The hydrogen production of a CdS/ZnCd-PBA catalyst with a ZnCd-PBA content of about 15% was 962 μmol under simulated light for 5 h, which was 13 and 916 times higher than those of CdS and ZnCd-PBA, respectively. At the same time, CdS/ZnCd-PBA-15 composites also showed good long-term stability. It shows that the construction of the S-scheme heterojunction promotes the separation of electron–hole pairs, which can effectively improve hydrogen production activity.