Facile preparation of a Co3O4/Mn0.5Cd0.5S heterojunction with highly efficient photocatalytic H2 production

Abstract

The development of low-cost, visible-light-responsive, high-efficiency catalysts for hydrogen production from photolyzed water is significant and challenging. In this study, a Co₃O₄/Mn_0.5Cd_0.5S heterojunction was synthesized by a facile stirring process. Through an electrostatic adsorption effect, Mn_0.5Cd_0.5S nanoparticles were tightly loaded on the Co₃O₄ surface. The introduction of Co₃O₄ enhanced the light absorption capacity of Mn_0.5Cd_0.5S and improved the photogenerated carrier separation efficiency. The Co₃O₄/Mn_0.5Cd_0.5S photocatalyst loaded with 30 wt% Co₃O₄ (COMCS-30) had the most excellent hydrogen production capacity, reaching 2696.6 μmol g⁻¹ h⁻¹, which was 5.2 times higher than that of Mn_0.5Cd_0.5S and 3.2 times that of Mn_0.5Cd_0.5S loaded with Pt (1.5 wt% Pt), respectively. In addition, the apparent quantum yield at 420 nm is 8.71%. Finally, based on related experimental results, a rational reaction mechanism is proposed. Obviously, this work shows that low-cost Co₃O₄, as an effective auxiliary catalyst, can replace noble metals for visible light catalytic hydrogen production in Mn_0.5Cd_0.5S solid solution.