SiO_2/TiO_2薄膜对水中腐殖酸降解及大肠杆菌灭活效果的研究

Study on Effect of SiO_2/TiO_2 Film on Photocatalytic Degradation of Humic Acid in Water and Inactivation of E. coli

采用溶胶-凝胶法制备了SiO2/TiO2粉体并采用XRD、TG-DTA及Uv-vis对其结构进行了表征。采用热沉积法将其负载于玻璃板上,以水中天然有机物腐殖酸和典型菌种大肠杆菌为代表物考察了SiO2/TiO2薄膜的光催化活性,并对其机理进行了推测。研究结果表明,SiO2/TiO2薄膜具有较高的光催化活性及抑菌作用。硅的引入不仅使催化剂的带隙变宽,提高了催化剂表面上光生e--h+的氧化还原能力,而且使催化剂表面出现了更多有利于光生空穴-电子转变为.OH的吸附氧,这是SiO2/TiO2薄膜使水中污染物降解及细菌灭活的主要原因。

The SiO2/TiO2 powder was prepared by sol-gel method and its structures were characterized using XRD, TG-DTA and UV-vis. The as-prepared SiO2/TiO2 was loaded on glass using hot deposition method. Natural organic humic acid in water and typical strains E. coli were chosen as represented objects in order to investigate the photocatalytic activity of SiO2/TiO2 film and its mechanism was suggested. Research show that SiO2/TiO2 film has high photoeatalytic activity and antibacterial function. The introduction of silicon not only increases the band gap of catalyst, improving the redox ability of e- h ＋ pairs, but also makes catalyst surface appeared more adsorption of oxygen in favor of e--h ＋ changing into · OH, which are useful for SiO2/TiO2 film photocatalytlc degradation of organic matter and inactivated bacteria in water.