Highly Efficient 2D/3D Structured CuCo<sub>2</sub>S<sub>4</sub>/CdIn<sub>2</sub>S<sub>4</sub> Composites with a p–n Heterojunction for Boosting Photocatalytic Hydrogen Evolution
Yansen Rao, Meng Sun, Bingzheng Zhou, Zhongpeng Wang, Tao Yan, Yu Shao
Abstract
Constructing novel surface microstructures for photocatalytic materials could significantly enhance the photocatalytic hydrogen production rate from water splitting. In this work, novel 2D/3D structured CuCo 2 S 4 /CdIn 2 S 4 p–n heterojunction photocatalysts for water splitting were successfully prepared by a solvothermal method. The coupling of a 2D CuCo 2 S 4 nanoplate on the surface of 3D flower-like CdIn 2 S 4 microspheres has strengthened the visible light absorption and promoted the charge separation efficiency due to their tight contacting area. The obtained CuCo 2 S 4 /CdIn 2 S 4 (CSCIS-2) photocatalyst exhibited a hydrogen production rate of 1320 μmol g –1 h –1, which was fivefold of that for pure CdIn 2 S 4 . Additionally, cyclic tests demonstrated improved photoactivity stability of the samples. A series of photoelectrochemical characterizations confirmed the effective suppression of charge carrier recombination in CuCo 2 S 4 /CdIn 2 S 4 composite catalysts. Finally, a rational photocatalytic mechanism was proposed based on the semiconductor band theory. This work contributes to the enrichment of sulfide-based research and applications in photocatalysis.