时间分辨红外光谱研究Cr价态在La,Cr共掺杂SrTiO_3光催化剂中的作用(英文)  

Time-resolved infrared spectroscopic investigation of roles of valence states of Cr in (La,Cr)-doped SrTiO_3 photocatalysts

作　　者：沈帅[1,2] 贾玉帅 范峰滔[1] 冯兆池[1] 李灿[1] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室洁净能源国家实验室,辽宁大连116023 [2]中国科学院大学,北京100049

出　　处：《催化学报》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)~~

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.

关 键 词：时间分辨光谱 铬掺杂 钛酸锶 光催化 

分 类 号：O643.36[理学—物理化学]