Enhanced activity of ZnS (111) by N/Cu co-doping: Accelerated degradation of organic pollutants under visible light

High-efficiency photocatalysts are of great significance for the application of photocatalytic technology in water treatment. In this study, N/Cu co-doped ZnS nanosphere photocatalyst (N/Cu-ZnS) is synthesized by a hydrothermal method for the first time. After doping, the texture of nanosphere becomes loose, the nanometer diameter is reduced, making the specific surface area of catalyst increased from 34.73 to 101.59 m(2)/g. The characterization results show that more ZnS (111) crystal planes are exposed by N/Cu co-doping; the calculations of density functional theory show that N/Cu co-doping can increase the catalytic activity of the ZnS (111) crystal plane, enhance the adsorption capacity of (111) crystal plane to O-2, and promote the generation of center dot O-2(-). The energy levels of the introduced impurities can be hybridized with the energy levels of S and Zn at the top of valence band and the bottom of conduction band, which makes the band gap narrower, thus enhancing the absorption of visible light. Compared with pure ZnS, the degradation rates of 2,4-dichlorophenol (2,4-DCP) and tetracycline (TC) by N/Cu-ZnS under visible light (>420 nm) are increased by 83.7 and 51 times, respectively. In this research, a promising photocatalyst for photocatalytic degradation of organic pollutants in wastewater is provided. (C) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Automated summary

N/Cu co-doped ZnS nanosphere photocatalyst (N/Cu-ZnS) was synthesized by a hydrothermal method for the first time. The doping process increased the specific surface area, exposed more ZnS (111) crystal planes, enhanced the adsorption capacity and catalytic activity, and narrowed the band gap for increased visible light absorption. The photocatalyst demonstrated significantly improved degradation rates of organic pollutants compared to pure ZnS under visible light.