Interaction of molecular oxygen with oxygen vacancies on reduced TiO2: Site specific blocking by probe molecules
Interaction of molecular oxygen with oxygen vacancies on reduced TiO2: Site specific blocking by probe molecules
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DOI：
10.1016/j.cplett.2009.07.002
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发表时间：
2009-08-06
影响因子：
2.8
通讯作者：
Murphy, Damien M.
中科院分区：
文献类型：
--
作者：
Green, Jason;Carter, Emma;Murphy, Damien M.
用CW EPR确定了超氧化物(O-2(-))在热还原的二氧化钛(P25)上稳定的表面位置的不均一性。存在两类主要的吸附中心：第一类是O-2(-)吸附在氧空位，[Vac中心圆点O-2(-)]，II-III是由于O-2(-)吸附在五个配位的Ti4+中心。通过用探针分子(CO2和Ar)选择性地阻断每个位置，可以防止电子从前驱体Ti3+中心转移到O-2(形成O-2(-))。CO2优先吸附在五个配位的Ti-非空位(3+)非空位中心，而Ar优先吸附在与氧空位相关的Ti3+中心(Ti-空位(3+))。(C)2009爱思唯尔B.V.保留所有权利。
A heterogeneity of surface sites for superoxide (O-2(-)) stabilization on thermally reduced TiO2 (P25) have been identified by cw EPR. Two main groups of adsorption sites exist; site I due to O-2(-) adsorbed at oxygen vacancies, [Vac center dot center dot center dot O-2(-)], and sites II-III due to O-2(-) adsorbed at five co-ordinate Ti4+ centres. Electron transfer from the precursor Ti3+ centres to O-2 (forming O-2(-)) can be prevented at each site through selective site blocking with probe molecules (CO2 and Ar). CO2 preferentially adsorbs at the five co-ordinate Ti-non-vacancy(3+) non-vacancy centres, while Ar preferentially adsorbs at the Ti3+ centres associated with the oxygen vacancies (Ti-vacancy(3+)). (C) 2009 Elsevier B. V. All rights reserved.