Low Temperature and Direct Synthesis of New Anatase Photocatalyst with Wide Solid Solution Range and Hybridization

点击翻译按钮获取中文摘要

Direct formation of titania solid solution nanoparticles doped with zirconium, scandium, and niobium, and co-doped with niobium and aluminum, and co-doped with niobium and scandium were carried out using mild hydrothermal method. The influence of dopants on the structure, morphology and properties such as photocatalytic activity were investigated. By thermal hydrolysis, anatase-type TiO_2 powder containing sulfur with the absorption in the visible region was directly formed. Anatase-type TiO_2 doped with ZrO_2 up to 9.8mol% was directly precipitated as nanometersized particles from the acidic precursor solutions in the presence and the absence of (NH_4)_2S_2O_8 by simultaneous hydrolysis under hydrothermal conditions. The favorable effect of doping ZrO_2 to anatase-type TiO_2 on the photocatalytic activity was observed. Scandium was doped into anatase nanoparticles up to 10mol% by hydrothermal crystallization from amorphous co-precipitates. Niobium-doped anatase-type titania nanoparticles were also directly formed under mild hydrothermal conditions using the hydrolysis of urea. The prominent effects of forming solid solutions with niobium oxide for anatase-type TiO_2 on the enhancement of photo-decomposition of MB under UV irradiation and adsorptivity in the dark were observed. The anatase-type Ti_<1-2x>Nb_xAlx_2 and Ti_<1-2x>NbxScxO_2 solid solutions, that were directly formed under mild hydrothermal conditions using the hydrolysis of urea, showed improved photocatalytic activity. The influence of their dopants on the phase stability of anatase was also estimated. Anatase-type titania/silica composite nanoparticles directly formed under mild hydrothermal conditions showed high photocatalytic activity and phase stability.