TiO2@SiO2复合材料的制备及其光催化与抗菌性能的研究

采用溶胶-凝胶法制备载体SiO₂, 并通过水解法制备出负载型TiO₂@SiO₂复合光催化抗菌材料, 采用SEM、XRD、BET、FT-IR、XPS和粒度仪对材料进行表征和分析。在UVA紫外光照下, 通过降解甲基橙溶液考察了复合材料的光催化性能, 在照射3 h后, 不同钛掺杂量复合材料的光催化降解率均能达到99.9%, 钛掺比为0.58时催化效率最高。通过平板涂布法检测了复合材料对大肠杆菌的抗菌效果, 发现抗菌性能随着钛含量的增加而提高, 在紫外照射条件下最高可达92%以上, 同时在可见光照射下也能表现出良好的抗菌性能。通过细菌荧光检测, 可以有效证明复合材料所产生的活性氧迁移到了细胞内部, 造成细胞体氧化损伤, 这是光催化材料抗菌机理研究的重要依据。

TiO2@SiO2 Composites: Preparation and Photocatalytic Antimicrobial Performance

Carrier SiO₂ was synthesized through Sol-Gel method, and the photocatalytic antibacterial material of TiO₂@SiO₂ composite was prepared by hydrolysis method. The synthesized composites were characterized. The photocatalytic properties of the composites were investigated by degrading methyl orange with UVA irradiation. After 3 h irradiation, all of composites with different amount of titanium doping can reach 99.9%. And the optimal catalytic efficiency of the composite is obtained when the titanium doping ratio (molar ratio) is 0.58. Antibacterial effect of composites on Escherichia coli, measured by plate coating method, shows that the antibacterial properties are improved with the increase of titanium content, which reach up to 92% under UVA irradiation. Moreover, the composites also exhibit favourable antibacterial properties under visible irradiation. Though fluorescence detection of bacterium, it is proved that the reactive oxygen species (ROS) produced by the composites migrate into the cells and cause the oxidative damage of the cells, which is a significant basis for the antibacterial mechanism of photocatalytic materials.