Reverse-Type-I MnCo<sub>2</sub>S<sub>4</sub>/CdS Heterojunction Nanorods for Highly Efficient Photocatalytic Hydrogen Production under Visible Light Irradiation
Yuye Cheng, Minghao Dou, Mengjie Yao, Kai Ding, Hongyu Shao, Yang Liu, Shenjie Li, Yanyan Chen
Abstract
Photocatalytic hydrogen production has great potential as a way to obtain green and sustainable energy. In this work, MnCo 2 S 4 /CdS type-I nanorod heterojunctions were successfully constructed, and the stability of the structure and photocatalytic performance of the composites were significantly improved by the timely transfer of photogenerated holes on the valence band and photogenerated electrons on the conduction band of CdS through the discontinuous MnCo 2 S 4 grown outside the nanorods. The photocatalytic hydrogen production of 5% loaded MnCo 2 S 4 /CdS under visible light (λ ≥ 420 nm) can reach 12 mmol·g –1 ·h –1, which is 42 times more efficient than the hydrogen production of pure CdS nanorods in the presence of Na 2 S and Na 2 SO 3 as hole scavengers. In addition, the apparent quantum efficiency of the composite catalyst with the best hydrogen evolution activity can reach 11.73%. The construction of type-I semiconductor heterojunctions in this study offers valuable guidance for the preparation of CdS photocatalysts that exhibit superior stability and photocatalytic efficiency.