担载Ag对TiO2界面光生电子转移效率的影响

通过采用原位电子顺磁共振（EPR）、紫外-可见漫反射（DRS）、低温液氮吸附技术对光化学还原法合成Ag/TiO2进行表征，比较不同反应气氛，Fe3＋为电子受体及微量H2O2存在情况下TiO2和Ag/TiO2光催化活性变化，阐述了Ag担载对TiO2界面光生电子的传输与捕获效率的影响. Ag捕获的光生电子具有较强流动性，可迅速向Ag/TiO2表面吸附的O2分子或表面Ti4＋传递，在Ag表面产生活性物种或在TiO2表面生成活性反应中心表相Ti3＋，减少光生电子在TiO2的体内俘获生成复合中心即体相内部Ti3＋的几率.适宜尺寸纳米Ag团簇的担载可有效加速光生电子的传输与捕获效率，提高活性物种数量.

Influence of Silver Deposition on the Transfer of Photogenerated Electrons for TiO2 Photocatalyst

In the present work, the influence of silver deposition on the transfer of photogenerated electrons was investigated. The catalyst was characterized by in-situ EPR, DRS, BET and phenol degradation under different conditions. The result showed that suitable size of silver cluster deposition can attract photogenerated electrons effectively and then the electrons transferred to the adsorbed oxygen and surface Ti4 efficiently. The recombination of the photogenerated electrons and holes was inhibited. The enhanced photocatalytic activity was mainly caused by the increased amount of reactive O2-. species, the higher amount of surface reactive center Ti3 and photogenerated holes.