AUTHOR=Tong Beibei , Shi Longfei , Liu Xiaohong 

TITLE=Sol–Gel Synthesis and Photocatalytic Activity of Graphene Oxide/ZnFe2O4-Based Composite Photocatalysts

JOURNAL=Frontiers in Materials

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2022.934759

DOI=10.3389/fmats.2022.934759

ISSN=2296-8016

ABSTRACT=<p>ZnO (ZO), Fe<sub>2</sub>O<sub>3</sub> (FO), and graphene oxide (GO)/ZO/FO/ZnFe<sub>2</sub>O<sub>4</sub> (ZFO) composite photocatalysts have been synthesized successfully <italic>via</italic> a simple sol–gel method and low-temperature technology. The phase structure and microstructural analysis confirmed that the GO/ZO/FO/ZFO magnetic separation photocatalyst is composed of GO, hexagonal ZnO, rhombohedral Fe<sub>2</sub>O<sub>3</sub>, and spinel ZnFe<sub>2</sub>O<sub>4</sub> without any other impurities. The GO/ZO/FO/ZFO composite photocatalysts have a high visible light optical absorption coefficient and photocatalytic activity for degrading dyes, refractory pollutants, and antibiotics. The degradation percentages of methyl orange, tetrabromobisphenol A, and oxytetracycline hydrochloride by the GO/ZO/FO/ZFO magnetic separation photocatalyst were 98% for 180 min, 99% for 150 min, and 85% for 180 min, respectively. The special synthesis path leads to the formation of a special heterojunction between GO, ZnO, Fe<sub>2</sub>O<sub>3,</sub> and ZnFe<sub>2</sub>O<sub>4</sub>, which does not change the optical band gap value of the main lattice Fe<sub>2</sub>O<sub>3</sub>, and enhances the surface defects of the GO/ZO/FO/ZFO magnetic separation photocatalyst, resulting in high charge carrier transfer and separation efficiency of the catalyst and then enhanced the photocatalytic activity of the GO/ZO/FO/ZFO magnetic separation photocatalyst.</p>