摘要
使用时间分辨红外光谱研究了经H2和O2处理的La和Cr共掺杂SrTiO3的光生电子动力学.X射线光电子能谱和Raman光谱结果表明,H2处理后样品中的Cr均是+3价,而O2处理后Cr为+3和+6价.使用355和532 nm激光激发样品所得时间分辨红外光谱表明,相比在Cr6+存在时,光生电子衰减速率在Cr3+存在的情况下要慢,这说明Cr3+更有利于抑制光生电子空穴的复合,从而增加光催化产氢的活性.
The kinetics of photogenerated electrons in SrTiO3(La,Cr) pretreated with either H2 or O2 were studied using time-resolved infrared spectroscopy.The X-ray photoelectron and Raman spectra showed that the Cr cations in the sample reduced with H2 were all in Cr3+,whereas those oxidized with O2 were in mixed of Cr3+ and Cr6+.Electrons excited with 355 and 532 nm light pulses showed the absorption of mid-IR light,and this was traced as a function of the time delay in a microsecond domain.The time-resolved results revealed that the decay rate of the photoinduced electrons with Cr3+ was slower than that with Cr6+,implying that trivalent Cr contributed more to retarding recom- bination of photoinduced electrons and holes,and enhanced photocatalytic H2 production activity.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第11期2036-2040,共5页
基金
supported by the National Natural Science Foundation of China (21090341, 21173213)
the National Basic Research Program of China (973 Program, 2009CB220010, 2009CB623507)~~
关键词
时间分辨光谱
铬掺杂
钛酸锶
光催化
Time-resolved spectroscopy
Chromium doping
Strontium titanate
Photocatalysis
