Improving the Photocatalytic H<sub>2</sub> Evolution of CdS by Adjusting the (002) Crystal Facet
Yuying Dang, Li Luo, Wei Wang, Wenfeng Hu, Xing Wen, Keying Lin, Baojun Ma
Abstract
In general, the activities for H2 evolution are dependent on the morphologies and exposed facet of semiconductor-based photocatalysts. Here, we reported that CdS with the (002) crystal facet and a small capacitance was vital for enhancing photocatalytic H2 evolution. After loading CoP as a co-catalyst, the H2 evolution activity of CoP/CdS-P (particle-like, dominant (002) facet) increased remarkably to 24 600 μmol/(h g), which was 1.28 times that of CoP/CdS-L (leaflike), 2.09 times that of CoP/CdS-R (rodlike), and 5.67 times that of CoP/CdS-S (spherelike). Electrochemical tests and surface photovoltage spectra demonstrated that CdS-P with a large proportion of the (002) facet and the smallest capacitance of 4.31 F/cm2 leads to the highest separation and transportation of photoexcited electrons. This study reveals the superiority of CdS with the (002) facet and gives an idea to design efficient semiconductor-based photocatalysts with a small capacitance.