Synthesis of Mo-doped TiO2 nanowires/reduced graphene oxide composites with enhanced photodegradation performance under visible light irradiation

摘要

In this research, anatase type Mo-doped TiO _(2) nanowires/reduced graphene oxide (Mo-TiO _(2) NWs/RGO) composites were successfully synthesized using a one-step alkali hydrothermal method followed by a calcination treatment at 500 °C, in which commercial TiO _(2) nanoparticles (Degussa P25) and graphene oxide (GO) were used as the precursors. GO was reduced to RGO during the alkali hydrothermal progress, and Mo was incorporated into the lattice of TiO _(2) nanowires (TiO _(2) NWs) simultaneously. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (DRS). The photocatalytic properties of the prepared catalysts were evaluated for the photodegradation of methylene blue (MB) under visible light irradiation. The results showed that Mo-TiO _(2) NWs/RGO composites exhibited much higher photocatalytic activity in comparison to the mono-modified or non-modified TiO _(2) NWs, the photodegradation efficiency of Mo-TiO _(2) NWs/RGO composites could reach up to 94.1% in 120 min, and no obvious deactivation was observed in the durability experiments. The mechanism of the enhanced photocatalytic activity, which arose from the synergistic effect of the morphology modification, Mo doping and graphene incorporation, was put forward.