Carbon-doped anatase TiO2 obtained from TiC for photocatalysis under visible light irradiation

Carbon-doped anatase TiO2 (C-TiO2) was prepared by mild oxidation of titanium carbide (TiC). The transformation of TiC to anatase TiO2 was complete when TiC was calcined in air at 350 °C for 8 h. The as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV−visible spectroscopy and BET adsorption measurement. The absorption spectrum of the C-TiO2 showed a stronger absorption in the UV–visible range and about 36 nm red shift of the spectrum onset compared with one of anatase TiO2 nanoparticles. The change of the spectra is attributed to ca. 0.7 wt.% carbon substitutions at oxygen sites in the sample. Compared with nanocrystalline anatase TiO2, the C-doped TiO2 powders exhibited photoactivity to trichloroacetic acid (TCA) degradation under visible light irradiation. The effects of iron doping on the sample and the pH of the solution on the photodegradation of TCA were also investigated.