Si掺杂介孔SO_4^(2-)/TiO_2的非模板剂法合成及表征  

Synthesis and Characterization of Silicon-Doped Mesoporous SO_4^(2-)/TiO_2 without Using Organic Templates

作　　者：陈垚翰[1] 沈俊[1] 张昭[1] 

机构地区：[1]四川大学化工学院,四川成都610065

出　　处：《催化学报》2008年第4期356-360,共5页

基　　金：国家自然科学基金(50474071).

摘　　要：在不使用模板剂的条件下,以工业硫酸氧钛溶液为原料合成介孔偏钛酸前驱体,再经正硅酸乙酯浸渍焙烧制备了具有良好热稳定性的Si掺杂介孔SO42-/TiO2.采用X射线衍射、N2吸附-脱附、扫描电镜、X射线能谱和傅里叶变换红外光谱等表征方法对样品的组成和结构进行了分析,并考察了该材料在亚甲基蓝氧化降解反应中的光催化性能.结果表明,在焙烧过程中,被吸附在偏钛酸孔道内的正硅酸乙酯发生水解,并与偏钛酸孔壁上的自由羟基形成Ti-O-Si键;Si进入二氧化钛骨架中,对孔结构起到了支撑作用,从而提高了介孔SO42-/TiO2的热稳定性.700℃焙烧2 h后,Si掺杂介孔SO42-/TiO2材料的比表面积仍达到189 m2/g,平均孔径为2.8 nm.400℃焙烧的样品在亚甲基蓝降解反应中表现出较好的光催化活性.Mesoporous metatitanic acid was prepared from industrial TiOSO4 solution without using templates. Then Si-doped mesoporous SO4^2-/TiO2 with high thermal stability was synthesized by impregnating mesoporous metatitanic acid with tetraethylorthosilicate solution and calcination. The calcined samples were characterized using X-ray diffraction, N2 adsorption and desorption, scanning electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy. The photocatalytic activity of Si-doped SO4^2-/TiO2 for the degradation of methylene blue was tested. Tetraethylorthosilicate that was adsorbed in the pores of metatitanic acid formed Ti-O-Si bond by reaction with free -OH on the pore walls ot7 metatitanic acid during calcination. Silicon atoms introduced into the framework of TiO2 act as the pore structure support, and thus the thermal stability of mesoporous SO4^2-/TiO2 was improved. The sample calcined at 700 ℃ for 2 h had a surface area of 189 m^2/g and an average pore diameter of 2.8 nm. The photocatalytic activity of the sample calcined at 400 ℃ was excellent.

关 键 词：介孔二氧化钛 硅掺杂 浸渍 热稳定性 光催化 

分 类 号：O643.36[理学—物理化学]