Synergistic effects of Fe and graphene on photocatalytic activity enhancement of TiO2 under visible light

A novel visible light-responsive GR-Fe/TiO2 composite photocatalyst was successfully synthesized by a simple hydrothermal method. Successful deposition of anatase TiO2 nanoparticles onto the graphene is confirmed by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). UV-vis diffuse reflectance spectroscopy (DRS) shows that compared with the pure TiO2, the resulting GR-Fe/TiO2 composite photocatalysts exhibit enhanced visible light absorption with the increasing Fe dopant. Fluorescence emission spectra show that GR-Fe/TiO2 composites possess improved charge separation than both GR-TiO2 and pure TiO2. The photocatalysis experiment demonstrates that GR-Fe/TiO2 composites have a ten-fold photocatalytic activity enhancement over pure TiO2 for the degradation of methyl orange. The enhanced photocatalytic activity may be attributed to the synergistic effect of improved adsorptivity of dyes, enhanced visible light absorption and effective charge separation. (C) 2012 Elsevier B.V. All rights reserved.