六方介孔氧化硅包覆纳米TiO_2复合物的合成及其光催化性能  

Synthesis of Nano-TiO_2 Coated by Hexagonal Mesoporous Silica and Its Photocatalytic Activity

作　　者：舒丽君[1] 魏坤[1] 郭武生[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640

出　　处：《硅酸盐学报》2011年第11期1806-1812,共7页Journal of The Chinese Ceramic Society

基　　金：中国高新技术计划(2007AA021908);国家自然科学基金(507-32003;U0834003)资助项目

摘　　要：采用分子自组装技术,以均匀分散的纳米TiO2溶胶作为合成六方介孔氧化硅(hexagonal mesoporous silica,HMS)的钛源,制备了比表面积高达1 479 m2/g的包覆纳米TiO2粒子的TiO2/HMS复合材料。对样品的结构及微观形貌进行研究。结果表明:尺寸为50 nm左右的TiO2粒子与HMS界面以Si—O—Ti键结合,高度分散在作为包覆层的HMS之中。HMS的Fourier变换红外光谱上960 cm–1处颇具争议的吸收峰,对应的是硅羟基发生再聚合反应所生成的存在于六方孔洞内部水的O—H键面内变形弯曲振动。经640℃煅烧4 h的TiO2/HMS复合材料样品具有最强的光催化活性,在测试浓度范围内,经紫外光光照140 min,甲基橙降解量达到58%。其原因是大的比表面积导致对氧气和水分的吸附能力增强,从而有利于高活性?OH自由基的生成。Nano-particles of TiO2 coated hexagonal mesoporous silica（HMS）（TiO2/HMS） composite with the specific surface area of 1 479 m2/g were prepared by a self-assembly method with dispersed nano-sol of TiO2 as a titanium source.The structure and mi-cro-morphology of the TiO2/HMS samples were investigated.The results show that the nano-particles with the average size of 50 nm are well dispersed in the HMS,and Si—O—Ti bonds are formed in the interface between TiO2 and HMS.The analysis by Fourier transform infrared spectroscopy indicated that a controversial absorption band located at 960 cm–1 in of HMS was O—H in-plane deformation bending vibration of water,which produced in the polymerization reaction of hydroxyl groups remained in the HMS.After 140 min radiation under ultraviolet light,the sample exhibited a superior photo-catalytic activity due to the greater specific sur-face area,which led to the absorption of O2 and H2O that favored to produce more ？OH free radicals.The sample sintered at 640 ℃ for 4 h was degraded by 58% of methyl orange

关 键 词：光催化剂 六方介孔氧化硅 纳米二氧化钛粒子 比表面积 甲基橙 

分 类 号：TQ174[化学工程—陶瓷工业]