▎ 摘　　要

In this study, a core-shell design of Fe3O4@SnO2 was prepared, doped with silver nanoparticles (Fe3O4@SnO2/Ag) and later laden into three-dimensional graphene oxide hydrogel (rGH) forming 10% rGH-Fe3O4@SnO2/Ag, which was synthesized using chemical reduction methods and utilized in the degradation of 2,4 dichlorophenol as a target pollutant in the solution. Fourier Transform Infrared Spectroscopy/FTIR spectra, Raman spectroscopy, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, X-ray diffraction, Photoluminescence spectra, Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy were some of the standardized characterization techniques utilized. 2,4 dichlorophenol (2,4-DCP) was quickly adsorbed by three-dimensional 10% rGH-Fe3O4@SnO2/Ag composite and rapidly degraded by Fe3O4@SnO2/Ag nanoparticles under sunlight irradiation, indicating that superb synergies between adsorption-photocatalysis degradation could significantly improve the pollutant degradation performance. The maximum adsorption capacity of 10% rGH-Fe3O4@SnO2/Ag was 14.90 mg/g after 30 min. According to the results, the percent degradation efficiency of 2,4-DCP in Fe3O4@SnO2/Ag-rGH was not only high i.e. 93.8% via the synergy amongst adsorption-photocatalytic degradation, but also the percent degradation efficiency of 2,4-DCP was 85% after 5 repetitive cycles, which signified a high synergistic effect between Fe3O4@SnO2/Ag nanoparticles and 3D graphene. A corresponding pathway for 2,4-DCP photodegradation was suggested, such as 2,4-dichlorophenol, formic, acetic, or oxalic acid as the main intermediate compounds. The experimental results of radical species trapping showed the photo-generated holes exhibiting an important role in promoting both direct oxidation of 2,4-DCP and production of O-center dot(2) radicals. Therefore, 10% rGH-Fe3O4@SnO2/Ag composite revealed that it has a photocatalyst with high degradation activity, facile recyclability and easy magnetic separation for its potential wide application in the water treatment. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.