Co-modified Commercial P25 TiO2 by Fe Doping and g-C3N4 Coating as High Performance Photocatalyst under visible light irradiation

The g-C 3 N 4 -coated and Fe-doped TiO 2 visible-light-driven photocatalysts were synthesized by a simple mixing method combined with calcination process, in which the commercial Degussa P25 TiO 2 was used as a titanium source. The new photocatalysts were investigated by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflection spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. The co-presence of uniform g-C 3 N 4 coating layers and doped metal ions was proved and the visible light absorption was significantly enhanced after modification. The photocatalytic efficiency and stability of the new photocatalysts in degradation of dyes and Cr(VI) under visible-light irradiation were remarkably enhanced, and were mainly dependent on the ratio of g-C 3 N 4 and metal ions. Based on the electrochemical impedance spectroscopy results, we believe the interfacial effect between g-C 3 N 4 and TiO 2 and the doping Fe ions in the heterojunction could improve the separation and transfer of photo-induced charge carriers and thereby enhanced the photocatalytic performance.