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

采用温和水热法直接制备了锆、钪、铌掺杂、铌铝共掺杂、铌钪共掺杂的二氧化钛固溶体纳米颗粒。考察了掺杂剂对其结构、形貌和光催化活性等性能的影响。通过热水解直接制备了含硫锐钛矿型TiO_2粉末，并在可见光区有吸附。在有（NH_4）_2S_2O_8和没有（NH_4）_2S_2O_8的酸性前驱体溶液中，通过水热同时水解，直接将掺入浓度高达9.8mol% ZrO_2的锐钛矿型TiO_2析出纳米颗粒。观察到ZrO_2掺杂锐钛矿型TiO_2对光催化活性的有利影响。采用水热结晶法从非晶态共析出物中掺钪至10mol%的锐钛矿纳米颗粒中。在温和的水热条件下，利用尿素水解直接制备了掺杂铌的锐钛矿型二氧化钛纳米颗粒。用氧化铌对锐钛矿型TiO_2形成固溶体，对增强紫外光下MB的光分解和暗处吸附性能有显著影响。在温和水热条件下，尿素水解直接生成锐钛矿型Ti_<1-2x>Nb_xAlx_2和Ti_<1-2x>NbxScxO_2固溶体，其光催化活性有所提高。并对其掺杂物对锐钛矿物相稳定性的影响进行了评价。在温和水热条件下直接形成的锐钛矿型二氧化钛/二氧化硅复合纳米颗粒具有较高的光催化活性和相稳定性。

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.