论文部分内容阅读
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 plane wave super soft pseudopotential method based on density functional theory (DFT) was used to simulate the adsorption behavior of H2O on the anaerobic and aerobic vacancies of anatase TiO2 (101). The adsorption energy, adsorption distance, The results show that the H2O molecule is not easily adsorbed on the surface of anaerobic vacancies anatase TiO2 (101), and is easily adsorbed on the surface containing oxygen vacancy defects. After stable adsorption , The H2O molecular plane is perpendicular to the surface of TiO2. The closer the negative center (O) is to the vacancy, the more stable the adsorption. The higher the oxygen vacancy concentration, the more obvious the adsorption effect. The electronic density of states (H2O) , The new peak appears near the Fermi level due to the 2p lone pair electrons of the O atom in the H2O molecule, which increases the transition probability of the material in the low energy region of visible light and obviously improves the absorption coefficient and reflectance of visible light , Optical gas sensing properties significantly.