Degradation of organic compounds on TiO2 photocatalysts prepared by a hydrothermal method in the presence of NH4F

Abstract

TiO2 photocatalysts were synthesized by a hydrothermal method from tetraisopropyl orthotitanate (TPOT) in the presence of NH4F with different NH4F/Ti molar ratios (0, 0.25, and 1). The formation of a well-crystallized anatase phase of TiO2 and the suppression of phase transition to rutile were observed, even at high calcination temperature, owing to the effects of NH4F. The TiO2 synthesized hydrothermally with NH4F exhibited absorption with a shift to the longer wavelengths of the visible-light region. The hydrothermally synthesized TiO2 with a moderate amount of NH4F exhibited high photocatalytic activity for the degradation of alcohol diluted in water under both UV-light and visible-light irradiations. © Springer Science+Business Media B.V. 2009.