金属和非金属共掺杂锐钛矿相TiO2的第一性原理计算

摘要

We present a first-principles calculation study of matal and nonmetal codoped anatase Ti02, We mainly investigate C/TM and N/TM （carbon and metal codoped, nitrogen and metal codoped） codoped TiO2, are calculate their bound energies, energy band structures and densities of states. We find that impurities of metal and the nonmetal have an aggregate tendenty by calculating the bound energy of codoping structure. Positive bound energy show that the doping atom and the peripheral atom will combine into a bond, the boding-effect-produced system energy is higher than the geometric-distortion-effect produced stress energy. We analyze the energy band structure and bonding of N/V and C/Cr -codoped TiO2, and further find if we want to extend TiO2 light absorb edge and improve TiO2 photocatalysis properties by metal and nonmetal codoped TiO2, we should make codoping by the codoped joint method, namely, on the bottom of the conduction band and on the top of valence band can arise impurity energy levels contributed by metal 3d and nonmetal 2p orbits respectively%本文运用第一性原理的计算方法，以C／TM和N／TM共掺杂（碳与过渡金属共掺杂和氮与过渡金属共掺杂）Ti02为例，分别计算了它们共掺杂TiO2的束缚能、能带结构和态密度等，通过对双掺杂结构的束缚能计算，发现非金属和金属杂质有团聚成键的趋势，其正的束缚能说明了掺杂原子与周围的原子成键，因成键作用减少的体系能量高于因几何畸变带来的应力能．在对N／V和C／Cr共掺杂能带结构和分子成键的详细分析中，发现非金属和金属共掺杂TiO2，要使掺杂后TiO2的光吸收边红移较大，光催化性能较好，就要符合金属和非金属共掺杂协同机制，即掺杂后在导带底下方和价带顶上方分别出现由金属3d和非金属2p态提供的杂质能级．