Water adsorption on TiO2 surfaces probed by soft X-ray spectroscopies: bulk materials vs. isolated nanoparticles.
Water adsorption on TiO2 surfaces probed by soft X-ray spectroscopies: bulk materials vs. isolated nanoparticles.
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DOI：
10.1038/srep15088
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发表时间：
2015-10-14
影响因子：
4.6
通讯作者：
Miron C
中科院分区：
文献类型：
--
作者：
Benkoula S;Sublemontier O;Patanen M;Nicolas C;Sirotti F;Naitabdi A;Gaie-Levrel F;Antonsson E;Aureau D;Ouf FX;Wada S;Etcheberry A;Ueda K;Miron C
我们描述了一种实验方法来探测水的吸附在隔离的，无衬底的二氧化钛纳米粒子（NPs）的表面上的软X射线光谱在气相中使用同步辐射。为了了解水和TiO 2表面之间的界面性质，在TiO 2 NPs的表面吸附水壳。我们使用两种不同的方式来控制NP的水合水平：在第一种方案中，将最初溶剂化的NP干燥，并且在第二种方案中，将由于商业气溶胶发生器而产生的干燥NP暴露于水蒸气。XPS用于识别游离TiO 2 NP表面上的水层壳的签名，并且使得可以跟踪它们的水合状态的演变。所获得的结果允许建立一个定性测定孤立的纳米粒子的表面状态，以及解开水吸附机制。这种方法似乎是一种独特的方法来研究一个孤立的纳米物体和溶剂覆盖层之间的界面，铺平了道路，在纳米材料的多相催化新的调查方法。
We describe an experimental method to probe the adsorption of water at the surface of isolated, substrate-free TiO2 nanoparticles (NPs) based on soft X-ray spectroscopy in the gas phase using synchrotron radiation. To understand the interfacial properties between water and TiO2 surface, a water shell was adsorbed at the surface of TiO2 NPs. We used two different ways to control the hydration level of the NPs: in the first scheme, initially solvated NPs were dried and in the second one, dry NPs generated thanks to a commercial aerosol generator were exposed to water vapor. XPS was used to identify the signature of the water layer shell on the surface of the free TiO2 NPs and made it possible to follow the evolution of their hydration state. The results obtained allow the establishment of a qualitative determination of isolated NPs’ surface states, as well as to unravel water adsorption mechanisms. This method appears to be a unique approach to investigate the interface between an isolated nano-object and a solvent over-layer, paving the way towards new investigation methods in heterogeneous catalysis on nanomaterials.