Magnetic Recoverable F-N Co-Doped ZnFe2O4/C/TiO2 Nanocomposites with UV-Vis Light Photocatalytic Activity

F-N co-doped TiO2/C/ZnFe2O4 (ZCT-FN) catalyst with excellent UV-Vis photocatalytic activity and recyclable performance was successfully synthesized by the sol-gel method. X-ray power diffraction results showed that ZCT-FN was anatase titanium dioxide with good crystallinity. X-ray photoelectron spectroscopy and UV-Vis revealed that F and N were co-doped into the lattice of TiO2, and a red shift of the absorption edge was brought out owing to F and N co-doping. Comparing to undoped TiO2/C/ZnFe2O4 and TiO2/ZnFe2O4, ZCT-FN exhibited an excellent photocatalytic activity for degradation of methyl orange both under UV- and Vis-light irradiation. Visible light photocatalytic degradation activity of ZCT-FN is nearly 4.2 times higher compared with P25. The high activity of ZCT-FN can be attributed to the synergetic effects of strong absorption and narrow band gap induced by F, N co-doping and narrow band gap semiconductor ZnFe2O4. The carbon layer between outer layer TiO2 and ZnFe2O4 core can effectively suppress the photodissolution behavior of catalyst. Moreover, ZCT-FN can be easily separated after the photocatalytic reaction and remain as stable photocatalytic activity after five cycles. This work not only offers a controllable method for the fabrication of F-N co-doped TiO2/C/ZnFe2O4 core-shell structure hybrids but also provides an effective and conveniently recyclable photocatalyst for the practical application in the purification of wastewater.