Gd, C, N and P quaternary doped anatase-TiO2 nano-photocatalyst for enhanced photocatalytic degradation of 4-chlorophenol under simulated sunlight irradiation

•Anatase-TiO2 doped with Gd, C, N and P was prepared by a sol–solvothermal method.•Enhanced photoactivity is ascribed to a synergetic effect of the quaternary doping.•Enhanced visible light absorption is due to its band-gap narrowed by N and P codoping.•The cooperative action of Gd and P further inhibits the charge carrier recombination.•The quaternary doped TiO2 has a superior photostability under sunlight irradiation.

A novel high-performance Gd, C, N and P quaternary doped anatase-TiO2 nano-photocatalyst was successfully prepared by a modified sol–solvothermal process. The physicochemical properties of as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, N2 physical adsorption–desorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV–vis absorbance spectroscopy, and photoluminescence spectroscopy. The photocatalytic activities of the samples were evaluated by degradation of 4-chlorophenol (4-CP) under simulated sunlight irradiation. Results indicated that Gd, C, N and P quaternary doped TiO2 with P-doping amount of 5 wt.% exhibited the highest photoactivity among as-prepared undoped, single-doped and codoped samples, implying that Gd, C, N and P quaternary doping produced a synergetic effect. The quaternary doped sample achieves an excellent photocatalytic performance with kapp of 0.0322 min−1, which is 2.75 times that of the commercial P25 TiO2 (kapp = 0.0117 min−1). The enhanced photoactivity of Gd, C, N and P quaternary doped TiO2 is attributed to the synergetic effect of enhanced visible light absorption, reduced charge carriers recombination, increased surface hydroxyls, and improved surface textural properties. This research provides a very effective and stable photocatalyst with visible light response for environmental application.

Graphical abstractGd, C, N and P quaternary tridoped TiO2 exhibits an enhanced visible light absorption property due to its band-gap narrowed by N and P codoping. The recombination of photogenerated electrons and holes can be further inhibited due to a cooperative action of Gd and P codoping.Figure optionsDownload full-size imageDownload as PowerPoint slide