基于第一性原理的Fe掺杂锐钛矿型TiO2(001)表面光催化性研究

摘要

基于密度泛函理论的第一性原理对不同掺杂方式和不同含 Fe量的 Fe/TiO2(001)禁带宽度及C6H6分子在其表面不同位置的吸附能进行了研究.Fe 原子掺杂纳米 TiO2的能带结构和态密度计算表明,表面间隙掺杂比替位掺杂更利于减小 TiO2的禁带宽度,且当掺杂浓度为 6.122%时,相比纯TiO2的禁带宽度减小幅度最大可达 59.3%.通过吸附能的比较得出了苯分子在TiO2(001)表面以水平吸附为主,在研究浓度范围内,随 Fe原子掺杂浓度的增加,吸附能并不像带隙一样呈减小的趋势,而是当 Fe原子掺杂浓度为4.167%时,吸附能的涨幅最大为 63.2%.%In this paper,the first-principles based on density functional theory was used to study the Fe/TiO2(001)band gap width and adsorption energy of C6H6 molecules at different positions on the surface of the molecule with different doping methods and different Fe content.Calculation of the band structure and density of states of Fe-doped TiO2 nanoparticles shows that,the surface gap doping is more favorable than the substitution doping to reduce the band gap of TiO2,and when the doping concentration is 6.122%, the maximum reduction of the band gap width is 59.3% higher than that of pure TiO2.According to the comparison of adsorption energy,it works out that the benzene molecule is mainly about horizontal adsorption on the surface of TiO2(001).Within the scope of the study,with the increase of Fe doping concentration,the adsorption energy does not decrease as the band gap,when the Fe atoms doping concentration is 4.167%,the maximum increase of adsorption energy is 63.2%.