摘要
基于密度泛函理论(DFT)的平面波超软赝势方法,从第一性原理计算的角度,应用GGA对Ti O2的高压相α-PbO2型Ti O2的晶格参数和电子结构作了比较系统的计算,得到优化后的晶格参数与实验值十分符合。电子结构计算表明α-PbO2型Ti O2属于间接带隙半导体,其禁带宽度为2.47 eV,大于锐钛矿型Ti O2计算的带隙值Eg=2.12eV,主要原因在于α-PbO2型Ti O2结构具有较低的晶体对称性,并且其Ti—O平均键长更长,Ti与O离子的正负电荷数较少,Ti3d轨道与O2p轨道杂化程度较弱。在理论上确认对称性较低的高压矿物—α-PbO2型Ti O2高压相的光催化效果不及常态相锐钛矿型Ti O2好。
On the basis of first-principle calculations,the cell parameters and electronic structure of α-PbO2-type TiO2 were calculated by using the plane-wave ultra-soft pseudo-potential method in line with the density functional theory （DFT） and with the generalized gradient approximation （GGA）. The optimized cell parameters were in good agreement with related experimental data. Electronic structure analysis revealed that α-PbO2-type TiO2 was an indirect wide-band semiconductor with a band gap of 2.47 eV,lager than the anatase TiO2 band gap, which may be caused by lower crystal symmetry, the average longer Ti-O band lengthand the weaker extent of mixing of the Ti3d and O2p orbits of high pressure orthorhombic α-PbO2-type TiO2. It was theoretically suggested that photocatalytic effect of α-PbO2-type TiO2 was not as good as that of anatase TiO2.
出处
《矿物岩石》
EI
CAS
CSCD
北大核心
2008年第3期14-18,共5页
Mineralogy and Petrology
基金
国家自然科学基金(批准号:40872039和40572114)
国家自然科学基金重大研究计划(批准号:90714002)
国家杰出青年科学基金(批准号:40425002)
高等学校博士学科点专项科研基金(批准号:20060491504)
