铁离子表面掺杂锐钛矿TiO_2(001)面的第一性原理研究

Incorporation of Iron Impurities at the Anatase TiO_2(001) Surfaces:A DFT study

基于周期性密度泛函理论,本文研究了Fe吸附于锐钛矿TiO2(001)面、替位掺杂表面Ti位,以及在横向晶隙和纵向晶隙内部掺杂的晶体结构变化及形成能,讨论了对应的能带结构及态密度的变化。为与表面氧空位进行对比,计算了氧空位存在条件下的能带结构及态密度。通过形成能的比较发现:Fe在吸附于晶体表面并向体内迁移时,倾向于掺杂在晶体表面晶隙位置。通过对电子结构及态密度的分析发现:Fe在晶体表面晶隙掺杂较表面氧空位掺杂更有利于TiO2光催化氧化效率的提高。

Base on the periodic density functional theory calculations,the structures,formation energies,band structures and density of states are investigated with iron adsorbed on the surface of TiO2（001）,substituted Ti sites of surface and subsurface,and in the vacancies of horizontal and longitudinal.For the comparisons,the band structures and density of states of O vacancy on the surface are calculated also.Our formation energy calculations suggest that the Fe atom prefers to transfer from the adsorbed surface to the vacancy.The analysis of the electronic structure and density of states of the Fe doped configure show that the photocatalytic activities of TiO2（001） is upgraded and becomes better than ones with Ovacancy.