三元杂化TiO2-SiO2-H3PW12O40材料的合成与表征

Synthesis and Characterization of Ternary Hybrid TiO2-SiO2-H3PW12O40 Materials

结合分步溶胶凝胶法和超声技术,以正硅酸乙酯、四异丙醇钛及磷钨酸为原料制备TiO2、TiO2-SiO2、TiO2-H3PW12O40及TiO2-SiO2-H3PW12O40材料,并用N2吸附测定(BET)、X射线荧光光谱(XRF)、X射线衍射(XRD)和NH3程序升温脱附(NH3-TPD)分析测试技术对材料进行了表征。结果表明:SiO2的加入有利于单一TiO2或TiO2-H3PW12O40样品的高度分散;制备的所有材料均出现锐钛矿晶型的TiO2特征衍射峰;含H3PW12O40样品中H3PW12O40以杂多酸微晶形式存在,掺杂杂多酸后样品弱酸位和强酸位强度均有一定增加。

TiO2,TiO2-SiO2,TiO2-H3PW12O40and TiO2-SiO2-H3PW12O40materials are prepared by means of step by step sol-gel method and ultrasonic technology,using tetraethyl orthosilicate,tetraisopropanoltitanate and phosphotungstic acid as raw materials.These materials are characterized by N2adsorption measurements(BET),X ray fluorescence(XRF),X ray diffraction(XRD),NH3temperature programmed desorption(NH3-TPD).The results show that the addition of SiO2is beneficial to the highly dispersed TiO2or TiO2-H3PW12O40.The characteristic diffraction peaks of titanium dioxide in the anatase crystalline form are observed in all prepared materials.H3PW12O40exist in the form of heteropoly acid microcrystalline in the samples containing H3PW12O40.After doping with heteropoly acid,the strength of weak and strong acid sites increases to a certain extent.