Preparation, characterization and visible-light activity of carbon modified TiO2 with two kinds of carbonaceous species

Visible-light responsive carbon modified TiO2 was synthesized through simple precipitation of tetrabutyl titanate in proper amount of water. The as-synthesized catalyst was characterized by elemental analysis, N2 adsorption–desorption analysis, X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS) and nuclear magnetic resonance (NMR). The results indicate that carbon modifies TiO2 in two ways: doping as interstitial carbon in the crystal lattice and coating as graphite-like carbon on the surface. It is found that the interstitial carbon could narrow the band gap, and the graphite-like carbon could serve as sensitizer. The sensitization effect of graphite-like carbon is found to contribute greatly to the excellent photocatalytic performance of carbon modified TiO2. It has been found that 95.6% of MO was decolorized within 120 min and 92.7% of Cr(VI) was reduced within 90 min in the presence of phenol. The formation mechanism of the carbon modified TiO2 has been discussed.

A novel and simple method was used to synthesize visible-light responsive carbon modified TiO2, which possesses excellent stability and high photocatalytic performance. Carbon elements in the sample calcined at 350 °C simultaneously present as interstitial carbon in the crystal lattice and graphite-like carbon on the surface. And graphite-like carbon contributes greatly to the high photocatalytic performance.Figure optionsDownload as PowerPoint slide