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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)TiO_2为例,分别计算了它们共掺杂TiO_2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TiO_2,要使掺杂后TiO_2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.
In this paper, using the first-principles calculation method, C / TM and N / TM co-doping (carbon and transition metal co-doping and nitrogen and transition metal co-doping) TiO 2 were calculated as co-doped TiO 2 Band structure and density of states, the binding energy of the doping structure can be calculated and it is found that the non-metallic and metallic impurities have the tendency to agglomerate into bonds. The positive binding energy shows that the doping atoms and the surrounding atoms In the detailed analysis of N / V and C / Cr codoped band structures and molecular bonding, it is found that the nonmetallic and Metal co-doped TiO 2, to make the light absorption edge of doped TiO 2 redshift, photocatalytic performance is good, it is necessary to co-metal and non-metallic co-doped synergistic mechanism, that is doped below the conduction band and The top of the valence band presents the impurity levels provided by the metal 3d and the non-metal 2p states, respectively.