Preparation of Transition Metal Doped Titania-Silica photocatalyst through Two-Liquids Phase Separation

在一个系统中，有一个稳定的两个液体不溶性区域，其液体温度、持有温度的变化和熔体的时间可以控制所述材料的相位分离纹理的大小和组成。在本研究中，一种可见的光活性光催化剂，包括氧化物半导体精细颗粒和玻璃矩阵，通过TiO_2-SiO_2系统中的相位分离熔融的组合制备了含有过渡金属和亚序热处理和选择性延伸的方法。0.1-1质量%的Nb被添加到粒度TiO_2光催化剂中的分析酶相位，该相位被快速组合成相位分离的40TiO_2-60SiO_2 （质量%）Melts and subsequent selective reaching。TiO_2的阶段是由XRD测试的。样品的光催化活性也从氢生成中得到了20%乙醇的明显解决方案，在500瓦高压汞灯的照明下得到了反应，在过渡金属掺杂样品中的反应率比较小，因为在非掺杂的一个中得到了反应，在比率之间的关系和过渡金属的数量不清楚。氢的产生是由发光的，不是可见光，而是紫外线1。剂量样品的一代比率有10个到10个，少于5个，这是非剂量样品的数目（ca.）1.5 mmol·g^<-1>·h^<-1>） ，并降低了转换金属的数量。由于从解剖学到规则的6级阶段过渡在掺杂的样品中并没有那么多，光催化活动的退化就意味着在样品中过渡金属部位的光激发的电子和洞重新组合。

In the system which has a stable two-liquid immiscibility region above its liquidus temperature, the variations of the holding temperature and the time of its melt can control the size and the composition of the phase separated texture of the quenched material. In this study, a visible light active photocatalyst, which comprises oxide semiconductor fine particles and glass matrix, was prepared through the quenching of the phase separated melt in TiO_2-SiO_2 system containing transition metal and the subsequent heat treatment and selective leaching.The Fe, Cr, V, Nb ions of 0.1-1 mass% to Ti were added to the granular TiO_2 photocatalysts comprising anatase phase which were synthesized by rapid quenching of phase-separated 40TiO_2-60SiO_2 (mass%) melts and subsequent selective reaching. The phase of TiO_2 was examined by XRD. The photocatalytic activities of the samples were also evaluated from the hydrogen generation from 20 vol% ethanol aqueous solution under the illumination of the 500W high pressure mercury lamp.The anatase ratios to rutile in the transition metal doped samples were smaller than that in non-doped one, though the relation between the ratio and the amount of transition metal was not clear. The hydrogen generation did occur by illumination of not the visible light but UV one. The generation rates of the doped samples were one tenth to five hundredth less than that of the non-doped sample (ca. 1.5 mmol・g^<-1>・h^<-1>) , and the rate decreased with increase of the amount of transition metals. As the degre6 of phase transition from anatase to rutile was not so much in the doped samples, the degradation of photocatalytic activity is considered to occur due to the recombination of photo-excited electrons and holes at the sites of the transition metal ions in the sample.