EDA-assisted synthesis of multifunctional snowflake-Cu2S/CdZnS S-scheme heterojunction for improved the photocatalytic hydrogen evolution

The charge separation efficiency is one of the main factors affecting the solar photocatalytic decomposition of water to produce hydrogen. Constructing a unique heterojunction can accelerate the separation and transfer of photo-generated charges, and effectively improve the photocatalytic efficiency, which is considered a potential strategy. Accordingly, the 2%Cu2S/CZS step-scheme (S-scheme) heterojunction based on morphology and electronic structure was successfully prepared via simple hydrothermal method. Compared with the monomer Cu2S and CdZnS, the hydrogen evolution rate of 2%Cu2S/CZS samples is significantly increased. In particular, the 2%Cu2S/CZS not only shows high hydrogen evolution rate of 5904 μmol g−1 h−1 (3.19 times than original CdZnS), but also presents preferable cyclic endurance. According to the characterization, we believe that the introduction of Cu2S has the following three advantages: (i) The snowflake structure of Cu2S reduces the agglomeration of granular CdZnS. (ii) The Cu2S with narrow band gap broadens the light response range of the composite catalyst. (iii) The Cu2S was introduced into CdZnS to form S-scheme heterojunction, which accelerated the separation and transfer of photo-generated charge. This work broadens the idea of designing efficient photocatalyst of hydrogen evolution.