TiO_2-SiO_2复合材料的制备及光催化性能

利用溶胶 凝胶技术,控制钛酸四丁酯(TBOT)与硅酸乙酯(TEOS)的水解速度,使其共同水解成溶胶、凝胶,以乙醇为溶剂进行超临界干燥,经过一定温度热处理后,得到暗黄色透明的块体材料·进行了透射电镜观察和X衍射分析,表明锐钛矿结构的纳米TiO2均匀地分散于无定形SiO2基质中·FT IR光谱分析发现纳米TiO2与SiO2基质之间存在着Ti O Si键·在对罗丹明B水溶液的光催化降解中,此块体材料显示较好的光催化活性,在1h内催化降解86%的罗丹明B·此材料克服了粉状TiO2在实际水污染治理应用中的局限性,有着广泛的应用前景·

Synthesis of TiO2-SiO2 Complex Material and Its Photocatalytic Property

The dark-yellow clear block TiO2-SiO2 complex material was prepared with two-step sol-gel technique. Controlling the hydrolysis speed, the tetrabutyl titanate (TBOT) and n-Ethyl silicate (TEOS) were hydrolyzed simultaneously and the sol produced was dried to form gel at 60°C. Then, the gel was dried by supercritical drying method using alcohol as solvent and annealed at different temperatures. The morphology and structure of TiO2-SiO2 complex material were confirmed by means of TEM, XRD and FT-IR. The results showed that after annealing the nano-TiO2 powder grains of anatase structure were uniformly dispersed in amorphous-SiO2 matrix and there was a Ti-O-Si bond between TiO2 grains and SiO2 matrix. In the photocatalytic degradation the TiO2-SiO2 complex material presents better catalytic property and nearly 86% Rhodamine B is degraded within 1 hour. This TiO2-SiO2 complex material is easier to separate from solution by filtration or sedimentation and it is expected to be used widely in waste-water treatment.