金包覆TiO_2纳米薄膜的光催化杀菌性能研究

Study on Photocatalytic Sterilizing Capability of Au-Coated TiO_2 Nano Thin Films

采用射频反应溅射法在玻璃衬底上制得均匀透明的TiO2纳米薄膜,然后采用金(Au)离子溅射镀膜法制得金包覆TiO2复合薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等研究了金包覆TiO2薄膜的结晶特性和表面形貌。研究显示,射频功率为200W时,射频薄膜表面光滑平整,由锐钛矿型TiO2纳米微粒构成,其微粒直径在20～100nm。Au离子溅射镀膜和真空退火后薄膜的表面形貌没有明显的变化。采用细菌涂布培养法对金掺杂TiO2纳米薄膜的光催化杀菌性能进行研究,结果表明金包覆TiO2纳米复合薄膜较单一TiO2纳米薄膜在光催化杀菌范围、速度及效率上具有明显的增强,对枯草芽孢杆菌在10min内的杀菌率均达到90%以上。根据实验结果,讨论了金包覆TiO2纳米薄膜光催化杀菌机理。

Au-coated TiO2 Nano-thin films are prepared by radio frequency（RF）sputtering and then Au ion is sputtered on glass substrates.The structural and the surface morphology of Au-coated TiO2 thin films are investigated by X-ray diffractometer（XRD）,scanning electron microscope（SEM）,etc.The results show that the TiO2 films with smooth surface consist of anatase TiO2 nano-particles with 200 W sputtering power.The diameter of nano-particle is in the range of 20--100 nm.The surface morphology has not been changed by Au ion sputtering and vacuum annealing.The photocatalytic sterilizing capability of the films is measured by Newcombe experiment.The results show that photocatalytic sterilization of the Au-coated nano-composite TiO2 thin film is enhanced compared with the single TiO2 film in the photocatalytic disinfection range,speed,and efficiency.Its killing rate to Bacillus subtilis in 10 min can achieve 90%.Based on the test results,the photocatalytic bactericidal mechanism of Au-coated TiO2 thin film is discussed.