Preparation, characterization and photocatalytic application of TiO2–graphene photocatalyst under visible light irradiation

A series of TiO2–graphene photocatalysts (TGPPC) were prepared from titanium dioxide and graphene oxide (GO) by a simple hydrothermal method. The structure, surface morphology and chemical composition were characterized by Fourier-transform infrared spectroscopy (FT-IR), ultraviolet–visible absorption spectra spectrum (UV–vis), UV–vis diffuse reflectance spectroscopy (DRS), X-ray diffractometer (XRD), Raman, scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS). XPS results confirm the interaction of TiO2 with graphene. The TGPPC was applied to the degradation of methylene blue (MB) under visible light irradiation; and the results indicate that TGPPC exhibits excellent photocatalytic activities for MB. The degradation efficiency of MB could be obtained 98.8% at a GO content of 20% and a time of 100 min. Photocatalytic degradation behavior of MB was investigated by the pseudo-first-order kinetics; and the photocatalytic degradation mechanism was proposed. The obtained results indicate that the prepared TGPPC has a potential application for the industrial effluents treatment containing MB.