S-Scheme Heterojunctions between Nanoparticles of Cd_0.8Mn_0.2S and Cu₂O for Photocatalytic Hydrogen Evolution

Cd0.8Mn0.2S is a ternary particulate chemical substance that faces significant challenges with carrier recombination in the field of photocatalysis. To address this issue, we formed an internal electric field and constructed S-scheme heterojunctions using Cu2O and Cd0.8Mn0.2S nanoparticles, thereby reducing the recombination rate of photogenerated carriers. We synthesized Cd0.8Mn0.2S using a hydrothermal method, followed by employing ultrasonic self-assembly to closely couple Cd0.8Mn0.2S with Cu2O. In this configuration, Cd0.8Mn0.2S acts as the electron acceptor and Cu2O acts as the electron donor. The Cd0.8Mn0.2S/Cu2O structure forms a tight interface, providing the shortest transfer distance for electron migration. The S-scheme heterojunction strategy effectively lowers the chemical reaction barriers and facilitates vectorial separation of photogenerated carriers. Under 10 W white light illumination, the Cd0.8Mn0.2S/Cu2O composite photocatalyst demonstrates remarkable hydrogen evolution activity, achieving a hydrogen production rate of 40.06 mmol·g–1·h–1. This S-scheme interface strategy paves the way for the structural design and large-scale application of highly active visible light photocatalysts.