载银二氧化钛光催化杀菌性能的研究

Study on photocatalytic sterilization performance of titanium dioxide load silver

以偏钛酸为前驱体,浸渍一定浓度的硝酸银溶液,用热沉积法制备出载银二氧化钛。用XRD测定载银二氧化钛的结构,扫描电镜观测形貌,研究了载银量、光强、二氧化钛浓度、细菌浓度对光催化杀菌的影响。结果表明:制备的粉体为超细锐钛矿型二氧化钛,颗粒为均匀的类球形,粒度约为100～200nm。在二氧化钛颗粒上负载约1.6%的银可以扩展光源利用范围至可见光,光催化作用与银协同杀菌;但银量过高,则主要体现银的杀菌效果。光强增加,杀菌效果提高;二氧化钛的浓度为1.5g/L时杀菌效果最好;细菌浓度低于106细胞/mL时,载银二氧化钛杀菌率可以达到90%以上。

Metatitanic acid as precursor, titanium dioxide loading silver grain was prepared by dipping into a stated concentrated silver nitrate solution and using heated-deposition on the surface of the titanium dioxide. The structure of titanium dioxide loading silver was measured by X-ray diffraction (XRD) and the shape was observed by scanning electron microscope (SEM). The influences of the contents of loading silver,light intensity,concentration of titanium dioxide and bacterial concentration on photocatalytic sterilization performance are investigated. The results show the powder of as-prepared titanium dioxide loading silver is super-fine anatase, and the shape is even sphere-like grains of which size is about 100～200 nm. The 1.6 percentage loading silver on titanium dioxide grain can enlarge the applied range of light to visible light and improve the performance of photocatalytic sterilization. However the silver content is higher, mainly antibacterial activity is carried out by silver. Increase of light intensity can improve the effect of sterilization,which is best at the concentration of titanium dioxide of 1.5 g/L. The rate of sterilization of titanium dioxide loading silver can achieve 90% at the concentration of bacteria under 10~6 cell/mL.