Novel and promising electrocatalyst for oxygen evolution reaction based on MnFeCoNi high entropy alloy
Novel and promising electrocatalyst for oxygen evolution reaction based on MnFeCoNi high entropy alloy
复制标题
基于MnFeCoNi高熵合金的新颖且有前景的析氧反应电催化剂
DOI：
10.1016/j.jpowsour.2019.05.030
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发表时间：
2019-08-01
影响因子：
9.2
通讯作者：
Pan, Ye
中科院分区：
文献类型：
--
作者：
Dai, Weiji;Lu, Tao;Pan, Ye
水裂解装置和金属-空气电池迫切需要基于地球丰富且低成本元素的高效析氧反应催化剂。本文首次报道了一种基于MnFeCoNi高熵合金的新型MOx（M = Mn，Fe，Co，Ni）纳米片催化剂。通过电化学循环伏安扫描活化，MOx纳米片可以直接在MnFeCoNi高熵合金颗粒表面生长，形成核壳结构。核壳结构表现出302 mV的低过电位，以实现10 mA cm（-2）的电流密度，83.7 mV dec（-1）的小塔菲尔斜率和在1 M KOH碱性溶液中电解超过20 h的优异长期稳定性，这与最先进的析氧反应电催化剂RuO 2相当。通过对MnFeCoNi高熵合金在循环伏安扫描活化前后的形貌、化学状态和元素组成的研究，了解材料的演变过程。本工作不仅提供了一种有前途的电催化剂，而且拓宽了高熵合金的应用领域。
Efficient oxygen evolution reaction catalysts based on earth-abundant and low-cost elements are urgently required for water splitting devices and metal-air batteries. Herein, for the first time we report a novel and promising MOx (M = Mn, Fe, Co and Ni) nanosheets catalyst for oxygen evolution reaction based on the MnFeCoNi high entropy alloy. By an electrochemical cyclic voltammetry scan activation, the MOx nanosheets can grow directly on the MnFeCoNi high entropy alloy particle surfaces forming a core-shell structure. The core-shell structure exhibits a low overpotential of 302 mV to achieve current density of 10 mA cm(-2), a small Tafel slope of 83.7 mV dec(-1) and exceptional long-term stability of electrolysis for over 20 h in 1 M KOH alkaline solution, which is comparable to the state-of-the-art oxygen evolution reaction electrocatalyst RuO2. We make an investigation of the MnFeCoNi high entropy alloy before and after cyclic voltammetry scan activation on their morphologies, chemical states and elements composition to understand the materials evolution. The present work not only provides a promising electrocatalyst but also broadens the application areas of high entropy alloys.