Abstract:
ZnFe
2O
4-TiO
2/reduced graphene oxide(rGO) composites were synthesized from TiO
2(P25), Fe(NO
3)
3·9H
2O, Zn(NO
3)
2·6H
2O and graphene oxide (GO) by one-step solvent thermal method. The properties and structures of ZnFe
2O
4-TiO
2/rGO composites were characterized by UV-Vis, Raman spectra, XRD, SEM and EDS. The photocatalytic degradation performance of ZnFe
2O
4-TiO
2/rGO composites prepared with different amount of GO were investigated. GO is reduced to rGO in the solvent thermal reaction process. The addition of ZnFe
2O
4 and rGO broadens the visible light wavelengths absorbed by ZnFe
2O
4-TiO
2/rGO composites. ZnFe
2O
4-TiO
2/rGO composites have magnetic performance, which is convenient for separation and recycling. ZnFe
2O
4-TiO
2/rGO composites show the best photocatalytic degradation of methylene blue(MB) when the mass fraction of GO is 5wt%, and the degradation rate reaches 99.1% after 60 min under simulated solar irradiation. According to the scavenger experiments, the possible MB degradation mechanism is mainly contributed to the generation of active species induced by·OH and·O
2-. The photo-generated electrons(e
+) in conduction band(CB) of TiO
2 migrate to valence band(VB) of ZnFe
2O
4, and form a Z-scheme photocatalytic system. The photocatalyst stability test shows that ZnFe
2O
4-TiO
2/rGO composites have excellent stability and can be used as a photocatalyst for the degradation of organic dyes under sunlight.