Ag/TiO2纳米粒子的制备与表征

为了扩大纳米TiO_2在可见光范围的吸收,进行在纳米TiO_2中掺入Ag实验.以工业级偏钛酸、硝酸银为主要实验原料,采用一种简易的方法制备出Ag/TiO_2纳米粒子,并通过X线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、紫外一可见光吸收光谱(UV-vis)对该粒子进行表征.结果表明,二氧化钛以锐钛型晶型,银以单质的形式存在于纳米复合粒子中;Ag的结合能367.476 eV(3d_(3/2))与373.453 eV(3d_(5/2))分别比纯银的结合能368.4 eV(3d_(3/2))与374.4 eV(3d_(5/2))低,这是由于制备Ag/TiO_2时煅烧温度较纯银高,银簇生长较大引起的;并显示复合粒子的粒径约为30 nm;Ag/TiO_2纳米粒子感应波长明显红移,增强了纳米TiO_2在可见光范围内的吸收.

Preparation and Characterization of Ag/TiO2 Nanoparticles

In order to enlarge the absorbed intensity of nano-TiO2 in visible light, Ag/TiO2 nanoparticles were prepared mainly from industrial H2TiO3 and AgNO3 by a simple method. It was characterized by X-ray powder diffraction(XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis. XRD patterns showed that TiO2 existed as anatase and silver existed as elemental form in nano composite particles. XPS results showed that the binding energies of silver were 367.476 eV (3d3/2) and 373.453 eV (3d5/2), which were lower than those of simple silver (368.4 eV and 374.4 eV), since the preparation temperature of Ag/TiO2 was higher than simple silver and led to Ag cluster growth. SEM and TEM results showed that the particle size of nano-composite particles was about 30 nm. Moreover, UV-vis refractive spectrums showed that its photocatalytic wavelength was apparently red shift, and the absorbed intensity of nano TiO2 in visible light was enlarged.