Photoactivity of carbon-coated anatase for decomposition of iminoctadine triacetate in water

Carbon-coated TiO2 were prepared by a simple heat treatment of the powder mixtures of anatase-type TiO2 (ST-01) with poly(vinyl alcohol) (PVA) at a temperature from 700 to 900 °C. Carbon-coated anatase TiO2 showed high photoactivity for the decomposition of iminoctadine triacetae (IT) in its dilute solution under UV irradiation. For all carbon-coated TiO2, the relation between relative concentration of IT in the solution and irradiation time could be approximated to be linear, its slope k corresponding to the rate constant of decomposition reaction of IT molecules. Photoactivity measured by the rate constant k was found to depend strongly on the full width at a half maximum intensity (FWHM) of 1 0 1 diffraction line of anatase phase, i.e., its crystallinity. The highest k value was obtained at around 0.5° in 2θ of FWHM. From repeated uses of the photocatalysts, it was experimentally proved that the pollutants, IT, adsorbed onto carbon layers coated on anatase were able to be decomposed under UV irradiation.