Coverage-dependent two-photon photoexcitation at the H2O/TiO2 interface
Coverage-dependent two-photon photoexcitation at the H2O/TiO2 interface
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DOI：
10.1016/j.susc.2016.02.018
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发表时间：
2016-10-01
期刊：
影响因子：
1.9
通讯作者：
Thornton, G.
中科院分区：
文献类型：
--
作者：
Payne, D. T.;Zhang, Y.;Thornton, G.
激发电子和空穴对于金属氧化物表面的氧化还原反应至关重要。然而，这种电荷转移过程的精确细节尚不清楚。我们报告双光子光电发射（HV = 3.23 eV）测量金红石型TiO 2（110）作为暴露于低于室温的水的函数。与桥接羟基的双光子共振增强水暴露后，达到最大的一个单层的名义覆盖。较高的覆盖率会减弱观察到的共振。紫外光电子能谱（HV = 21.22 eV）的初始，带隙状态的变化不大，一个单层水覆盖。这是可能的，增强引起的解离内的吸附水单层，虽然不能排除其他机制。(C)2016年6月，作者。由爱思唯尔公司出版
Excited electrons and holes are crucial for redox reactions on metal oxide surfaces. However, precise details of this charge transfer process are not known. We report two-photon photoemission (hv = 3.23 eV) measurements of rutile TiO2(110) as a function of exposure to water below room temperature. The two-photon resonance associated with bridging hydroxyls is enhanced following water exposure, reaching a maximum at a nominal coverage of one monolayer. Higher coverages attenuate the observed resonance. Ultraviolet photoemission spectroscopy (hv = 21.22 eV) of the initial, band gap states shows little change up to one monolayer water coverage. It is likely that the enhancement arises from dissociation within the adsorbed water monolayer, although other mechanisms cannot be excluded. (C) 2016 The Authors. Published by Elsevier B.V.