A convenient N2–CCl4 mixture plasma treatment to improve TiO2 photocatalytic oxidation of aromatic air contaminants under both UV and visible light

A convenient N2–CCl4 mixture plasma treatment to improve TiO2 photocatalytic oxidation of aromatic air contaminants under both UV and visible light was reported. X-ray diffraction (XRD), N2 adsorption, UV–vis spectroscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared TiO2 catalysts. The microstructures of the TiO2 catalysts were preserved after plasma treatments. Chlorine ions did not doped into TiO2 lattice but located on TiO2 surface via the coordination with Ti4+ sites. The doping N content of prepared TiO2 catalyst increased obviously by using this N2–CCl4 mixture plasma method. The activities were tested in the photocatalytic oxidation of benzene and toluene under both UV and visible light. Chlorine radicals which formed under illumination are effective in oxidizing aromatic side groups, but ineffective in reactions with the aromatic ring.