NH3处理温度对N掺杂P25-TiO2的可见光催化活性的影响

研究了NH3处理温度对N掺杂P25-TiO2可见光催化活性的影响以及可见光催化活性与表面组成和结构的关系．实验结果表明：NH3处理温度在600℃时，有最高活性；在700℃，P25-TiO2转变为以金红石相为主，表面未发生N掺杂，这与700℃时NH3分解有关；N掺杂浓度、可见光吸收两者与可见光催化活性之间均不存在顺变关系．讨论揭示：N掺杂P25-TiO2的可见光催化活性是由三个要素协同作用产生：（i）表面生成大量束缚单电子氧空位（Vo），（ii）表面有N掺入，（iii）晶型以锐态矿为主，三者缺一不可．

Influence of NH_3-treating temperature on visible light photocatalytic activity of N-doped P_25-TiO_2

The influence of NH3-treating temperture on visible light photocatalytic activity of N-doped P25-TiO2 as well as the relationship between the surface composition structure of TiO2 and its visible light photocatalytic activity were investigated. The results showed that N-doped P25-TiO2 treated at 600℃ has the highest activity. The structure of P25-TiO2 was converted from anatase to rutile at 700℃, moreover, no N-doping was detected at the surface of P25-TiO2. There was no simply linear relationship between the visible light photocatalytic activity and the concentration of doped nitrogen, and visible light absorption. The visible light photocatalytic activity of N-doped P25-TiO2 was mainly influenced by the synergistic action of the following factors： （i） the formation of the single-electron-trapped oxygen vacancies （denoted as Vo ）, （ii） the doped nitrogen on the surface of TiO2, （iii） the anatase TiO2 structure.