A novel magnetic ZnFe2O4 aerogel photocatalyst for visible light reduction of Cr(VI) at high concentrations: Facile synthesis, enhanced activity and photocatalytic mechanism, combined with first-principles calculations

• Published in: Ceramics international Vol. 48; no. 3; pp. 3974 - 3984
• Main Authors: Huang, Shun-tian, Tai, Ju-xiang, Hao, Wen-ke, Lu, Jia-xin, Liu, Si-jia, Wu, Xiao-dong, Cui, Sheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2022
• Subjects: Cr(Ⅵ) photoreduction; Formic acid; Magnetic separation; Visible light; ZnFe2O4 aerogels; Cr(Ⅵ) photoreduction; Visible light; ZnFe2O4 aerogels; Magnetic separation; Formic acid
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2021.10.184

Herein, we prepared a novel magnetic ZnFe2O4 aerogel capable of visible light reduction of Cr(VI) via the sol-gel method. The influences of different heat treatment temperatures on the physical phase, structure, and properties of the catalysts were systematically investigated. Photocatalytic experiments revealed that the 400 °C heat-treated ZnFe2O4 aerogel exhibited the optimal photocatalytic performance. To attenuate the influence of catalyst adsorption on the photocatalytic experiments, the concentration of Cr(VI) solution was as high as 100 mg/L. The reduction rate of Cr(VI) was significantly higher than that of some previously reported ZnFe2O4 photocatalysts after visible light irradiation for 120 min. A plausible photocatalytic reaction mechanism was deduced based on the first-principles DFT calculations and photoelectrochemical experiments. In addition, the 400 °C heat-treated ZnFe2O4 aerogel possessed a high specific surface area of 115.31 m2/g and a saturation magnetization intensity of 10.6 emu/g, which allowed for recovery by magnetic separation.