ZnTiO3-TiO2纳米复合材料的光催化性能

通过溶胶 凝胶（Sol-Gel）法制备了ZnTiO3-TiO2纳米复合光催化剂，利用透射电子显微镜、X射线衍射、紫外-可见吸收光谱和ζ电位等测试技术对其形貌、晶体结构及其光谱响应特性进行了表征。 以亚甲基蓝（MB）溶液的脱色降解为模型反应，考察了光源和焙烧温度对该纳米复合材料光催化性能的影响。 结果表明，所得纳米复合材料的催化性能与材料的尺寸、在介质中的分散性能、表面荷电性质等有关。 600 ℃下焙烧3 h所得的ZnTiO3-TiO2纳米复合材料尺寸小（约60 nm）、分散性能好、表面荷负电荷量最高、催化性能最好，且在太阳光下的活性高于紫外光下的。 如太阳光下7 h可使亚甲基蓝（MB）溶液的脱色降解率达到93%，而在紫外光下只有82%；并且其催化活性高于纯TiO2和ZnO的。 该纳米复合催化剂重复使用4次仍能使亚甲基蓝（MB）溶液的脱色降解率在80%以上。 因此，具有较好的光催化稳定性能。

Photocatalytic Property of ZnTiO3-TiO2 Nano-composite Materials

ZnTiO3-TiO2 nano-composite photocatalytic materials were prepared via a Sol-Gel method and characterized by transmission electron microscope(TEM), X-ray diffractometry(XRD), UV-Vis spectrum and zeta(ζ) potential. The influences of light source and calcination temperature on the photocatalytic property of the nano-composite materials was investigated by decolorizing degradation of methylene blue(MB) solution as a probe. The results exhibit that the catalytic activity of the as-prepared material depends on the particle size, dispersibility in solution as well as the superficial charge. On the surface of the ZnTiO3-TiO2 obtained by calcinin at 600 ℃ for 3 h, which can disperse well in solution and has an average particle size of 60 nm and highest negative charge, decolorizing efficiency of MB solution was up to 93% under sunlight radiation for 7 h while the efficiency was just 82% under ultraviolet light radiation for same time radiation. Such efficiency can be maintained higher than 80% when the catalyst is repeatedly used for 4 times. The nano-composite material shows higher photocatalytic activity than pure TiO2 and ZnO, and has preferable photocatalytic stabilization property under sunlight.