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

Abstract

Cd 0.8 Mn 0.2 S 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 Cu 2 O and Cd 0.8 Mn 0.2 S nanoparticles, thereby reducing the recombination rate of photogenerated carriers. We synthesized Cd 0.8 Mn 0.2 S using a hydrothermal method, followed by employing ultrasonic self-assembly to closely couple Cd 0.8 Mn 0.2 S with Cu 2 O. In this configuration, Cd 0.8 Mn 0.2 S acts as the electron acceptor and Cu 2 O acts as the electron donor. The Cd 0.8 Mn 0.2 S/Cu 2 O 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 Cd 0.8 Mn 0.2 S/Cu 2 O 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.