H_2O分子在锐钛矿型TiO_2(101)表面的吸附特性与微观机理  

Adsorption characteristic and microcosmic mechanism of anatase TiO_2(101) surface adsorption of H_2O molecules

作　　者：杨英[1] 冯庆[1] 张菊花[1] 

机构地区：[1]重庆师范大学物理与电子工程学院,重庆400047

出　　处：《原子与分子物理学报》2015年第4期695-702,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(61274128;61106129);重庆市自然科学基金(CSTC2013JCYJA0731;CSTC2014JCYJA50015);重庆市教委科学技术研究项目(KJ120614;KJ1400524)

摘　　要：本文采用基于密度泛函理论(DFT)的平面波超软赝势方法,模拟计算H2O分子在锐钛矿型TiO2(101)无氧空位和有氧空位表面的吸附行为,对吸附能、吸附距离、吸附前后表面电子态密度以及光学性质分别进行分析,结果表明:H2O分子在无氧空位锐钛矿型TiO2(101)表面不容易被吸附,在含有氧空位缺陷的表面容易被吸附;稳定吸附后,H2O分子平面垂直于TiO2表面;负电中心(O端)距空位越近,吸附越稳定,且氧空位浓度越高,吸附效果越明显;通过电子态密度分析发现,H2O分子吸附于含氧空位的表面后,由于H2O分子中O原子的2p孤对电子掺入,新峰值在费米能级附近出现,提高了材料在可见光低能区域的跃迁几率,明显改善了对可见光的吸收系数和反射率,光学气敏传感特性显著.In this paper, the adsorption energy, adsorption distance, density of states and optical properties were studied from the plane wave ultra -soft pseudo -potential technology based on the density function theory （ DFT）. The results through simulation calculation of H2O adsorbed on the anatase TiO2 （ 101 ） surface show that the surface only containing oxygen vacancy can stably adsorbs H2O molecules. After stable adsorption, the H2O molecule plane is perpendicular to TiO2 （101） surface. The closer the negative charge center （0 -terminal） to the surface, the more easily the adsorption; and the higher of oxygen vacancy concentration, the more obvious adsorption effect. Compared with the density of states, a new peak appears nearby the fermi level because of 2p lone - pair electrons of H2O molecules doping in surface. The transition probability, optical gas sensitive features, absorption coefficient and reflectivity can be improved in the low-energy scope of visible light.

关 键 词：锐钛矿 光学气敏传感材料 表面吸附 密度泛函理论 

分 类 号：O469[理学—凝聚态物理]