The large-scale application of water electrolysis technology is limited by the slow kinetics of the oxygen evolution reaction (OER) that cause vast energy loss. Rational design and construction of hierarchical heterostructures are helpful for developing efficient OER electrocatalysts due to their interesting morphological features and electrochemical properties. Herein, we prepared hierarchical CoS@(Fe,Ni)S heterostructures on carbon fiber paper (CoS@(Fe,Ni)S/CFP) with particle-on-wire morphology using prussian blue analogue as template and precursor. The unique hierarchical heterostructure maximizes accessible active sites and the synergistic effect between different components significantly improves electrocatalytic activity. Impressively, CoS@(Fe,Ni)S/CFP electrocatalyst requires a small overpotential of 237 mV to achieve a current density of 20 mA cm with a low Tafel slope of 54 mV dec and the corresponding voltage has no obvious change after 60 h stability test under a constant current density of 50 mA cm in 1 M KOH solution. This work provides a new idea for the design of efficient and stable non-noble metal-based OER electrocatalysts.

中文翻译：

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普鲁士蓝类似物辅助构建分级CoS2@(Fe,Ni)S2异质结构以实现高效电催化析氧反应

水电解技术的大规模应用受到析氧反应（OER）动力学缓慢的限制，导致巨大的能量损失。分层异质结构的合理设计和构建因其有趣的形态特征和电化学性质而有助于开发高效的OER电催化剂。在此，我们使用普鲁士蓝类似物作为模板和前驱体，在碳纤维纸上制备了具有颗粒在线形态的分层 CoS@(Fe,Ni)S 异质结构（CoS@(Fe,Ni)S/CFP）。独特的分层异质结构最大限度地提高了活性位点的可及性，不同组分之间的协同效应显着提高了电催化活性。令人印象深刻的是，CoS@(Fe,Ni)S/CFP电催化剂需要237 mV的小过电位才能实现20 mA cm的电流密度和54 mV dec的低塔菲尔斜率，并且相应的电压在稳定60小时后没有明显变化在 1 M KOH 溶液中以 50 mA cm 的恒定电流密度进行测试。该工作为高效稳定的非贵金属基OER电催化剂的设计提供了新思路。