Utilization of reduced graphene oxide for the enhancement of photocatalytic property of TiO2 nanotube

Photocatalysts based on TiO2 nanotubes and reduced graphene oxide (TNTs-RGO) were prepared by the hydrothermal method. The resulting TNTs-RGO composite photocatalysts were characterized by X-ray powder diffraction, transmission electron microscopy, diffuse reflection spectrum, Fourier transform infrared spectroscopy, N-2 adsorption-desorption isotherm, and fluorescence spectrum. The photocatalytic activity of TNTs-RGO was investigated through the degradation tests of Rhodamine B (RhB) and Cr(VI) under UV-light irradiation. The results showed that compared with TNTs or TiO2, TNTs-RGO possessed higher surface area, enhanced optical absorption in the visible-light region and improved separation efficiency of electron-hole pairs, leading to the remarkable increases in adsorption capacity and photocatalytic activity for RhB or Cr(VI), which was thanks to the introduction of RGO. On the basis of the experimental results, a possible photocatalytic degradation mechanism of RhB or Cr(VI) by TNTs-RGO was also proposed. The excellent absorption capacity and photocatalytic activity suggested the great potential applications of TNTs-RGO photocatalyst in environmental problems.