TiO_2-SiO_2复合材料的制备及光催化性能

Synthesis of TiO_2-SiO_2 Complex Material and Its Photocatalytic Property

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·

The dark-yellow clear block TiO_2-SiO_2 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℃. Then,the gel was dried by supercritical drying method using alcohol as solvent and annealed at different temperatures. The morphology and structure of TiO_2-SiO_2 complex material was confirmed by means of TEM,XRD and FT-IR. The results showed that after annealing the nano-TiO_2 powder grains of anatase structure are uniformly dispersed in amorphous-SiO_2 matrix and there is a Ti-O-Si bond between TiO_2 grains and SiO_2 matrix. In the photocatalytic degradation the TiO_2-SiO_2 complex material presents better catalytic property and nearly 86% Rhodamine B is degraded within 1 hour. This TiO_2-SiO_2 complex material is easier to separate from solution by filtration or sedimentation and expected to be used widely in waste-water treatment.