Efficient CdS Nanoparticle/Zn(OH)F Heterojunction Catalysts for Hydrogen Evolution

Photocatalytic water splitting H2 production based on semiconductor nanoparticle heterojunctions is an attractive strategy. Various morphologies of Zn­(OH)F have been widely used in photocatalytic degradation of organic matter; however, its application in photocatalytic hydrogen production has been rarely reported. Herein, two kinds of morphologies catalysts, one rodlike CdS/Zn­(OH)F (CdS/RZF) and the second flower-like heterojunction CdS nanoparticle/Zn­(OH)F (CdS NP/FZF), were prepared by the simple and mild hydrothermal method. Interestingly, CdS NP/FZF exhibited superior photocatalytic activity to CdS/RZF due to the flower-like structure of Zn­(OH)­F, which prevented the aggregation of CdS nanoparticles, thereby exposing more active sites. Notably, the light absorption ability of CdS nanoparticle/Ni x Zn1–x (OH)F (CdS NP/NZF) was greatly improved, which was due to the introduction of Ni2+. As a result, the H2 production rate of CdS NP/NZF (2410 μmol·g–1·h–1) was increased by 2.19 times compared to that of CdS NP/FZF. This remarkable enhancement of photocatalytic H2-evolution activity of CdS NP/NZF was attributed to its special morphology in addition to Ni2+ doping, which promoted the separation of photogenerated electrons and holes, as well as improved the ability of visible-light response. This work provides a family of catalysts as a promising candidate for photocatalytic hydrogen evolution.