Novel Magnetically Separable Reduced Graphene Oxide (RGO)/ZnFe₂O₄/Ag₃PO₄ Nanocomposites for Enhanced Photocatalytic Performance toward 2,4-Dichlorophenol under Visible Light

Novel magnetically separable nanocomposite photocatalyst reduced graphene oxide (RGO)/ZnFe2O4/Ag3PO4, prepared by the solvothermal and in situ precipitation method, was first investigated as the photocatalyst for 2,4-dichlorophenol (2,4-DCP) degradation under visible light irradiation. The catalysts with different mass ratios were systematically characterized with FT-IR, XPS, XRD, SEM, FESEM, UV–vis, and PL. The nanocomposite RGO/ZnFe2O4/Ag3PO4 showed enhanced photocatalytic activity and stability compared with pure Ag3PO4 under the same conditions. During the photocatalysis process, intermediates of 4-chlorophenol (4-CP) and some other low molecular weight acids, including maleic acid, glyoxylic acid, glycolic acid, oxalic acid, acetic acid, and formic acid were detected through GC/MS. According to these analyses and the capture experiments of reactive species, the photocatalytic mechanism of RGO/ZnFe2O4/Ag3PO4 was discussed on the basis of the heterojunction energy-band theory and Z-scheme theory, and a possible degradation pathway of 2,4-DCP was also proposed.