Characterization and visible light photocatalytic properties of nanocrystalline TiO2 synthesized by reactive plasma processing

Nanocrystalline titanium oxide powder has been synthesized by reactive plasma processing. The precursor powder of TiH2 is oxidized ‘in-flight’ in a thermal plasma reactor to generate nanocrystalline titania powder. The synthesized powder consists of nano-sized particles of anatase and rutile phases of titanium dioxide. Photocatalytic activity of the plasma-synthesized powder was evaluated by studying the degradation of methylene blue dye solution under direct sunlight as well as UV irradiation. FTIR spectroscopy and X-ray photoelectron spectroscopy have been used to analyze the catalytic activity of the plasma-synthesized powder. UV–visible diffused reflectance spectra of the plasma-synthesized TiO2 samples showed that they absorb in the visible region leading to effective photocatalytic activity in sunlight. The results corroborated that the plasma-synthesized powder can be effectively used for outdoor applications.