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用密度泛函理论(DFT),采用平面波超软赝势(PWPP)方法,模拟计算了Ag掺杂金红石TiO2对能隙、Fermi能级的影响,探讨其电子结构及光谱特性的变化.Ag掺杂使Fermi能级移入价带,带隙变窄,原因在于价带的上方引入了独立的杂质能级,使其带隙Eg减小了0.89eV.由于Ag的掺杂,光生电子由Fermi能级较高的TiO2纳米管表面转移至Fermi能级低的金属Ag内.紫外-可见光谱分析表明,由于Ag掺杂,TiO2对光的吸收发生红移39nm,其表观带隙变窄,证明在导带与价带之间存在杂质能级.XPS分析表明,—OH能够增强TiO2纳米管表面的酸活性点,有助于光催化氧化能力的提高.
Density functional theory (DFT) and plane wave super soft pseudopotential (PWPP) method were used to simulate the influence of Ag-doped rutile TiO2 on the energy gap and Fermi energy level, and to investigate the changes of their electronic structure and spectral characteristics. Miscellaneous fermi level into the valence band, band gap narrowed due to the introduction of an independent impurity level above the valence band to make its bandgap Eg reduced by 0.89eV. Due to Ag doping, photogenerated by the Fermi energy The higher TiO2 nanotube surface is transferred to Ag with low Fermi level.Ultraviolet-visible spectroscopy analysis shows that the absorption of light by TiO2 is red shifted by 39 nm due to Ag doping, and its apparent bandgap narrows, which proves The impurity level exists between the conduction band and valence band.XPS analysis shows that -OH can enhance the acid active sites on the surface of TiO2 nanotubes and contribute to the improvement of photocatalytic oxidation ability.