钼搀杂TiO_2光催化活性的研究

The Photocatalytic Activity of TiO_2 Doping with Molybdemnum Ion

用溶胶 -凝胶法制备了一系列不同钼搀杂量的TiO2 光催化剂 ,以甲基橙降解为探针反应 ,结果表明 :搀入少量的钼 ,可显著提高TiO2 的光催化活性 ,钼搀杂质量分数为 0 5%～ 1 5%时 ,光催化降解效果最好 ;钼的搀杂质量超过 2 % ,光催化活性逐渐降低 .以Raman光谱、紫外反射谱、X射线衍射等方法研究了TiO2 的微观结构 ,结果表明 :少量钼的搀杂 ,钼离子进入TiO2 的晶格 ,Mo6+ 成为电子授体 ,提高了TiO2 的光催化活性 ;但钼搀杂量增加 ,MoO3 晶相在TiO2 表面形成 ,两种氧化物间有可能形成异质结 ,降低了催化剂的光催化活性 .

TiO 2 doping Mo 6+ catalysts with Mo 6+ loading in the range of 0%～7% were prepared, characterized and tested for the degradation of azo dye\|methyl orange.The photocatalytic activity reach the maximum at the optimal content (ca 0 5%) of Mo 6+ . The results of polycrystalline X\|ray diffraction and UV\|Vis reflectance and Raman spectral analysis showed that the increase in activity is related to the changes in the lattice and the deformation of crystal surface.The mechanism of catalytic properties was discussed.