Ag掺杂APS改性的TiO2颗粒的制备及其光催化降解作用

为提高Ag/TiO2纳米颗粒的光催化降解作用,采用聚合凝胶工艺路线,以钛酸四丁酯为前驱体,硝酸银为银源,通过向反应体系引入鳌合剂醋酸、表面改性剂γ-氨丙基三乙氧基硅烷(APS)以及还原剂甲醛等添加剂,制备出TiO2粉体及Ag/TiO2纳米复合粉体。利用FT-IR、XRD、TG-DTA、TEM和UV-Vis-NIR等手段对样品进行表征。结果表明,经γ-氨丙基三乙氧基硅烷改性的TiO2颗粒掺Ag后分散性得到改善,粒径约1 nm的Ag颗粒较均匀地分布在10～15 nm TiO2颗粒上;可见光的利用和锐钛矿热稳定性都得到提高;Ag/TiO2纳米颗粒在光照下对甲基橙具有良好的光催化降解效果。

Preparation and Effects on Photocatalytic Degradation of Ag-Doped TiO2 Powders Modified with APS

To improve the effects of Ag/TiO2 on photocatalytic degradation,using Ti(OC4H9)4 as raw material and silver nitrate as silver source,nano-TiO2 and nano-sized Ag/TiO2 particles were prepared via polymer gel process by adding acetic acid as chelating agent,3-aminopropyltriethoxysilane as surface modification agent and formaldehyde as reducing agent to the reaction system.The nano-powders of TiO2 and Ag/TiO2 were characterized by Fourier transform infrared(FT-IR) spectroscopy,X-ray diffractometry(XRD),thermogravimetry-differential thermal analysis(TG-DTA),transmission electron microscopy(TEM) and ultraviolet-visible-near infrared(UV-Vis-NIR) absorption.The results indicate that the composite powders of the surface modified Ag-doped TiO2 with 3-aminopropyltriethoxysilane improve the dispersion of the TiO2 particles,and silver particles,with average grain diameter of 1 nm,are distributed on surfaces of TiO2 particles of 10~15 nm;Absorption of visible light and heat stability of anatase are improved.Ag/TiO2 shows a good effect on the photocatalytic degradation of methyl orange solution under xenon lamp irradiation.