A rapidly room-temperature-synthesized Cd/ZnS:Cu nanocrystal photocatalyst for highly efficient solar-light-powered CO2 reduction

Publication date: 5 December 2018
Source:Applied Catalysis B: Environmental, Volume 237
Author(s): Xianguang Meng, Guifu Zuo, Peixiao Zong, Hong Pang, Jian Ren, Xiongfeng Zeng, Shanshan Liu, Yi Shen, Wei Zhou, Jinhua Ye
An ideal photocatalyst that can promisingly convert CO2 should have suitable band gap and fully consider the activation of reaction. However, well-designed photocatalytic materials with these aspects are very limited. This study reports a highly efficient CO2 reduction photocatalyst based on ZnS nanocrystals which can be rapidly synthesized at room temperature and operated under solar light irradiation at all-inorganic reaction system. Two functional elements, Cu and Cd, are respectively used as dopant and cocatalyst of ZnS nanocrystal for selective CO2 reduction. Cu⁺ doping expands the photoabsorption of ZnS into visible light region and the simultaneous Cd²⁺ surface modification significantly improves the activity of CO2 reduction with 99% formic acid selectivity. A combination of charge density distribution and electronic state studies reveal that the Cd s orbital displays obviously higher density of states near band-edge with a relatively lower lying band center than that of Zn s orbital. This will greatly favor the charge transfer from conduction band of ZnS to the surface state created by Cd²⁺ for catalyzing CO2 reduction.

Graphical abstract

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