Boosting Photocatalytic Hydrogen Production over Mn0.4Cd0.6S/CuS p–n Heterojunction under Visible Light Irradiation

Photocatalytic hydrogen production from water splitting is a promising technology for overcoming energy and environmental issues. Herein, Mn 0.4 Cd 0.6 S/CuS composites were constructed for photocatalytic hydrogen production. The amount of CuS is optimized, and the composition and structure of the Mn 0.4 Cd 0.6 S/CuS composite are investigated via various characterization techniques. The formation of a p–n heterojunction between Mn 0.4 Cd 0.6 S and CuS and the built-in electric field improve the separation efficiency of photogenerated electrons and holes and enhance the performance of photocatalytic hydrogen production. When the content of CuS is 5 wt%, Mn 0.4 Cd 0.6 S/5CuS presents the best photocatalytic hydrogen production rate of 22.10 mmol h −1 g −1 , which is 3.0 times greater than that of Mn 0.4 Cd 0.6 S, and the apparent quantum yield reaches 7.82% at 400 nm. Combined with the activity test and characterization results, the reaction mechanism of photocatalytic hydrogen production over the Mn 0.4 Cd 0.6 S/CuS composite is proposed.