A CdS/MnS p–n heterojunction with a directional carrier diffusion path for efficient photocatalytic H2 production

Abstract

Photocatalytic reactions usually involve the reduction of photogenerated electrons and the oxidation of photogenerated holes. The migration process of photogenerated holes is slower than that of photogenerated electrons, and the oxidation potential is higher. So accelerating the oxidation reaction can improve the photocatalytic activity. In this work, the CdS nanorod/MnS hybrid photocatalyst is prepared by a hydrothermal method. The H₂ production rate is 5.92 mmol g⁻¹ h⁻¹ with the apparent quantum efficiency of 5.63% at 420 nm, which is 10.57 times and 49.33 times higher than that of CdS nanorods and MnS, respectively. A CdS/MnS p–n heterojunction is prepared. The photogenerated carriers can move effectively between CdS and MnS, which is confirmed by SPV and TPV. In addition, the oxidation reaction potential can be significantly reduced by loading MnS. The photocatalytic hydrogen production activity can be significantly improved.