Growth and Reactivity of Titanium Oxide Ultrathin Films on Ni(110)
Growth and Reactivity of Titanium Oxide Ultrathin Films on Ni(110)
复制标题
Ni(110)上氧化钛超薄膜的生长和反应活性
DOI：
10.1021/jp067802m
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Papageorgiou A
中科院分区：
文献类型：
--
作者：
Papageorgiou A
利用软X射线光电子能谱（SXPS）、X射线吸收近边结构（XANES）和低能电子衍射（LEED）研究了在Ni（110）表面生长的TiO 2薄膜。根据初始钛覆盖率，观察到两种不同膜的形成，准六方相和具有金红石（110）棒的膜。光谱（SXPS和XANES）的结果表明，所有的膜由完全氧化的钛。此外，在190 K下暴露于分子水后，研究了部分由金红石TiO 2（110）组成的较高覆盖度相的反应性。在低压（小于10- 7 mbar）下，观察到分子水和羟基的形成。高压暴露（在10- 6毫巴的量级上）导致薄膜的羟基化，发现这在退火时是可逆的。
Soft X-ray photoelectron spectroscopy (SXPS) and X-ray absorption near-edge structure (XANES) have been combined with low-energy electron diffraction (LEED) to examine the growth of titanium dioxide thin films on Ni(110). Depending on the initial titanium coverage, the formation of two different films is observed, a quasi-hexagonal phase and a film with rutile (110) rods. Spectroscopy (SXPS and XANES) results indicate that all films consist of fully oxidized titanium. Furthermore, the reactivity of the higher coverage phase, consisting partly of rutile TiO2(110), was investigated after exposure to molecular water at 190 K. The formation of molecular water and hydroxyls was observed for low-pressure exposure (less than 10-7mbar). High-pressure exposure (on the order of 10-6mbar) resulted in hydroxylation of the thin film, which was found to be reversible upon annealing.