银修饰氮掺杂TiO_2薄膜的制备及光催化性能研究

Synthesis and Photocatalytic Properties of Ag-Modified N-Doped TiO_2 Thin Films

TiO2具有光催化活性，因而被广泛应用于废水处理、空气净化、尾气处理等领域。研究表明，经掺杂的TiO2薄膜具有更优异的光催化活性。在众多的可掺杂元素中，N和Ag具有独特的性能特征，因此其可使TiO2薄膜的光催化活性得到较大提升。本文使用直流磁控溅射法和拼靶工艺制备了不同Ag含量的银修饰掺氮TiO2薄膜，并分析了薄膜的形貌结构、表面元素化学态、光学性能和可见光催化活性。研究表明：薄膜沉积过程中Ag含量对薄膜性能影响较大。在TiO2的表面，颗粒细小而均匀。随着Ag含量的增加，薄膜表面出现凸起颗粒，为A＆0颗粒，且其尺寸逐渐增大；薄膜对350—800mm波段光的吸收增强。当舷含量为6．76％（原子比）时，薄膜具有最高的可见光催化活性。

The Ag-modified N-doped TiO2 thin films were deposited by DC magnetron sputtering of the TiO2 target, partly covered with a silver plate.The impact of the synthesis conditions,including but not limited to the Ag-content, N2 partial pressure and sputtering power, on the microstructures and optical properties of the films were investigated. The frlms were characterized with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and ultra- violet visible spectrophotometer. The results show that the Agocontem strongly affects its microstructures and optical prop- erties. For example, as the Ag-content increased from 0.0 to 6.76 % （at）, first, randomly-distributed, small bumpy Ag20 clusters formed on TiO2 surface, then, gradually conglomerated, and finally, grew into islands or patches, accompanied by an increasing enhancement of photo-catalysis activity and absorptance in 350 ~ 800 nm range. The optimized photo-cataly- sis activity was obtained by growing the films with 6.76 % of Ag.