Surface characterization of titanium dioxide powder treated by the CH4–H2 plasma CVD method

Anatase is a naturally occurring crystalline form of titanium dioxide (TiO2) powder was treated by microwave-induced low temperature plasma of methane–hydrogen mixed gas. The light grayish sample was observed by the hydrogen-rich plasma treatment. Since the superior photocatalytic activity of TiO2 under ultraviolet irradiation is well known, we examined the photocatalytic characterization of the samples. On the gas-phase decomposition of acetaldehyde a good evaluation of the plasma-treated sample was obtained under ultraviolet irradiation. Moreover, the light grayish sample showed photocatalytic activity under visible light irradiation. Plasma-treated samples were characterized by XRD, FT–IR, FT-Raman and XPS measurements.