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

Abstract A convenient N 2 –CCl 4 mixture plasma treatment to improve TiO 2 photocatalytic oxidation of aromatic air contaminants under both UV and visible light was reported. X-ray diffraction (XRD), N 2 adsorption, UV–vis spectroscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared TiO 2 catalysts. The microstructures of the TiO 2 catalysts were preserved after plasma treatments. Chlorine ions did not doped into TiO 2 lattice but located on TiO 2 surface via the coordination with Ti 4+ sites. The doping N content of prepared TiO 2 catalyst increased obviously by using this N 2 –CCl 4 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.