Mo-X(B,C,N,O,F)共掺杂TiO_2体系的光催化协同效应研究

Research on the photocatalysis synergistic effect of Mo-X(B,C,N,O,F) codoped TiO_2

采用密度泛函理论平面波超软赝势方法,计算并分析了Mo/X(B,C,N,O,F)共掺杂TiO_2体系的形成能、电子结构和光学性质,研究了共掺杂协同效应对于计算体系光催化性能的影响机制.首先计算出不同掺杂体系的态密度及能带结构,利用能带理论分析了共掺杂效应对于禁带宽度的调控作用,进而分析了共掺杂对TiO_2光催化能力和稳定性的协同作用.结合电荷密度图,分析原子间的电荷转移情况,得到计算体系中各原子成键状态.最后,结合光吸收谱线分析得出Mo/C共掺杂类型在调制TiO_2体系中可见光波段的光催化性能上优势明显,在催化作用上表现出协同效应.本文的理论研究对共掺杂方法在TiO_2光催化领域有着一定的指导意义.

The plane-wave ultrasoft pesudopotentials based on the density functional theory is used to study the formation energy, the electronic structure and the optical properties of molybdenum and different nonmetallic elements codoped anatase TiO2, where the nonmetallic elements are boron, carbon, nitrogen, oxygen and fluorine. Firstly, we calculate the total densities of states and the band structures of different kinds of codoping TiO2, and analyse the codoping modulation effect on band gap by using the energy band theory. Furthermore, we analyse the synergistic effects on stability and catalysis of TiO2 caused by codoping. And then the state of each atom＇s bond effect is obtained by analysing the total density map. Finally, we come to the conclusion that molybdenum-carbon codoping structure is superior to others on modulating the photocatalysis of TiO2 in visible light. Our theoretical research will be instructive and meaningful for photocatalysis area of TiO2 in the future.