N/Zr共掺杂锐钛矿型TiO_2光催化协同作用机制的第一性原理研究

First-principles investigations on the photocatalysis synergistic effect on N/Zr codoped TiO_2

采用平面波超软赝势法计算了N,Zr单掺杂和共掺杂锐钛矿型TiO2的电子结构和光学性质.根据能量最低原理比较了不同替位掺杂构型的最稳定结构,而后分析单、共掺杂构型中各自的能带结构,通过计算态密度及分波态密度分析了其光学性质改善机制.此外通过分析体系的电荷密度图得出N与Zr有团簇成键的趋势.对不同掺杂体系的光学性质进行了对比分析,发现共掺杂方法可以有效增强TiO2材料对可见光的吸收以促进其更好的利用太阳能.本文的理论计算和分析将有助于理解共掺杂方法提高TiO2光催化效应的协同作用机制.

The Density Functional Theory based on the Plane-wave Ultra Soft Pseudopotential method were used to investigate the electronic structures and optical properties of N-doped,Zr-doped and N/Zr co-doped anatase TiO2 in this article.Firstly,the most stable configuration was found out among different doping ones based on the Principle of Lowest Energy by calculating their total energy.Then we analyze the band structure,density of states and partial density of states of N/Zr doped and co-doped anatase TiO2,while the method of improving optical properties was discovered through analyzing these calculations.By analyzing the total density map,we concluded that N and Zr in co-doped anatase tend to form a bond.The comparisons in their optical properties demonstrate that co-doping can help anatase TiO2 to make a better use of visible light efficiently.The theoretical calculations and analysis in this article will help to understand the mechanism of how co-doping method improve the photocatalysis of TiO2.