Snowflake-like Cu2S/Zn0.5Cd0.5S p-n heterojunction photocatalyst for enhanced visible light photocatalytic H2 evolution activity

Building a p-n heterojunction can accelerate the separation and transfer of photoinduced charges, which is considered to be a promising approach to constructing photocatalysts with excellent H-2 evolution activities. Herein, novel snowflake-like Cu2S/Zn0.5Cd0.5S heterojunction photocatalysts were successfully synthesized. Compared to the pure Cu2S and Zn0.5Cd0.5S, the as-synthesized Cu2S/Zn0.5Cd0.5S showed remarkably improved H-2 evolution rate. Cu2S/Zn0.3Cd0.5S with a Cu2S content of 3 wt% showed the optimized H-2 evolution rate of 4923.5 mu mol g(-1) h(-1) in Na2S-Na2SO3 solutions, and the corresponding apparent quantum efficiency is 30.2% at 420 nm. The experimental results indicate that the enhanced H-2 evolution rates can be attributed to the fabrication of the p-n heterojunction between Cu2S and Zn0.5Cd0.5S, effectively boosting photogenerated charge carriers separation and transfer. Moreover, a plausible mechanism was proposed. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.