原位光譜研究多元素薄膜中的界面電化學反應

Abstract

近年來，多元素薄膜的新材料設計策略已廣泛應用於各個領域。隨著多元素材料的蓬勃發展，鑑定材料的表面反應性以及反應機制變得致關重要。傳統上常用的表面分析儀器往往需要在真空下進行測量，需要除去表面的溶液，導致觀察結果與實際的界面反應只有間接關係。此外，隨著系統中混合元素增加，鑑定材料將變得更加困難。同時各元素之間的交互作用也更加複雜。因此，我們開發一個具有一系列原位技術的分析平台，以識別材料表面實際發生的反應。透過整合多種即時分析方法，我們不僅成功鑑定出鎳、鉻、鐵、銅甚至多元素薄膜的電化學行為，並提出元素之間可能存在的協同效應。最後，透過可見光譜在氧化與還原之間的跳躍電位下追蹤鎳氧化還原動力學，證實鐵的存在不僅會抑制羥基氧化鎳的生成量，還會降低羥基氧化鎳的生成速率。

In recent, a new material design strategy of multi-principal elements (MPE) thin films have been widely applied in various fields. With the rising development of MPE materials, it is essential to characterize the surface reactivity and reaction mechanism on the materials. Conventionally, the commonly used surface analysis instruments often sholud be measured under vacuum, it is necessary to remove the solution on the surface, causing the observation is indirectly related to the actual interfacial reaction. Besides, with the increasing elements mixed in the system, it will become harder and harder to characterize the material. Meanwhile, the interaction between each element is also more complex. Therefore, we develop an analytical platform with series of in-situ techniques to identify the actual reaction occurring on the material’s surface. Through multiple combinatorial real-time analytical approaches, we successfully not only investigate the electrochemical behavior of Ni, Cr, Fe, Cu, even MPE thin film, but also propose the possible synergistic effect among the elements. Finally, Ni redox kinetics are monitored by visible spectroscopy under the sudden potential jumps between oxidation and reduction, we confirm that the presence of Fe species not only inhibits the amount of NiOOH formation, but also reduces the formation rate of NiOOH.