Schuster Ralf, Wähler Tobias, Kettner Miroslav, Agel Friederike, Bauer Tanja, Wasserscheid Peter, Libuda Jörg
Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany.
Institute of Chemical Reaction Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058, Erlangen, Germany.
ChemistryOpen. 2021 Feb;10(2):141-152. doi: 10.1002/open.202000187. Epub 2020 Sep 10.
Low-temperature synthesis in ionic liquids (ILs) offers an efficient route for the preparation of metal oxide nanomaterials with tailor-made properties in a water-free environment. In this work, we investigated the role of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [C C Pyr][NTf ] in the synthesis of cobalt oxide nanoparticles from the molecular precursor Co (CO) with ozone. We performed a model study in ultra-clean, ultrahigh vacuum (UHV) conditions by infrared reflection absorption spectroscopy (IRAS) using Au(111) as a substrate. Exposure of the pure precursor to ozone at low temperatures results in the oxidation of the first layers, leading to the formation of a disordered Co O passivation layer. Similar protection to ozone is also achieved by deposition of an IL layer onto a precursor film prior to ozone exposure. With increasing temperature, the IL gets permeable for ozone and a cobalt oxide film forms at the IL/precursor interface. We show that the interaction with the IL mediates the oxidation and leads to a more densely packed Co O film compared to a direct oxidation of the precursor.
在离子液体（ILs）中进行低温合成，为在无水环境中制备具有定制性质的金属氧化物纳米材料提供了一条有效途径。在这项工作中，我们研究了1-丁基-1-甲基吡咯烷鎓双（三氟甲基磺酰）亚胺[C₄C₁Pyr][NTf₂]在由分子前驱体Co₂(CO)₈与臭氧合成氧化钴纳米颗粒过程中的作用。我们在超清洁、超高真空（UHV）条件下，以金（111）为基底，通过红外反射吸收光谱（IRAS）进行了一项模型研究。在低温下将纯前驱体暴露于臭氧会导致第一层被氧化，从而形成无序的Co₃O₄钝化层。在臭氧暴露之前，通过在前驱体膜上沉积一层离子液体层，也能实现对臭氧的类似保护。随着温度升高，离子液体对臭氧变得可渗透，并且在离子液体/前驱体界面处形成氧化钴膜。我们表明，与离子液体的相互作用介导了氧化过程，并且与前驱体的直接氧化相比，导致形成了更致密堆积的Co₃O₄膜。
