The development of low‐cost and highly reactive electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in basic media is still a great challenge. Herein, we design a three‐dimensional Co₃O₄@NiFe‐LDH (LDH: layered double hydroxide) core‐shell nanostructure on Ni foam, in which the core Co₃O₄ nanowires play a key role in the stability and the shell NiFe‐LDH nanosheets provide the main active sites for electrocatalytic water splitting. The as‐prepared Co₃O₄@NiFe‐LDH exhibits excellent electrocatalytic activity for OER with a low overpotential of 269 mV at a current density of 100 mA cm⁻², a small Tafel slope of 66 mV dec⁻¹, and excellent stability without degradation over 40 h. Furthermore, the sample also demonstrates robust performance for HER with a low overpotential of 74 mV at a current density of 10 mA cm⁻². Most importantly, when employing the Co₃O₄@NiFe‐LDH/NF as both anode and cathode, only 1.56 V is needed to achieve a current density of 10 mA cm⁻², which is lower than the combination of Pt/C and IrO₂ catalysts for overall water splitting. This work provides a significant strategy toward the rational design of novel core‐shell electrocatalysts for overall water splitting.

中文翻译：

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合理设计分层Co3O4 @ NiFe层状双氢氧化物核壳纳米结构，改善了总水分解中的电催化性能

在碱性介质中开发用于氢气释放反应（HER）和氧气释放反应（OER）的低成本，高反应性的电催化剂仍然是一个巨大的挑战。在本文中，我们在镍泡沫上设计了三维Co ₃ O ₄ @ NiFe‐LDH（LDH：分层双氢氧化物）核壳纳米结构，其中，Co ₃ O ₄核纳米线在稳定性和壳层中起着关键作用NiFe‐LDH纳米片提供了电催化水分解的主要活性中心。所制备的Co ₃ O ₄ @ NiFe-LDH在100 mA cm ^-2的电流密度下具有269 mV的低过电势，对OER表现出优异的电催化活性。，Tafel斜率很小，为66 mV dec ^-1，稳定性出色，在40小时内不会降解。此外，该样品还展示了在10 mA cm ^-2的电流密度下具有74 mV的低过电势的HER的强大性能。最重要的是，当同时使用Co ₃ O ₄ @ NiFe-LDH / NF作为阳极和阴极时，仅需要1.56 V即可实现10 mA cm ^-2的电流密度，该电流密度低于Pt / C和Pt / C的组合。用于整体水分解的IrO ₂催化剂。这项工作为合理设计用于整体水分解的新型核壳型电催化剂提供了重要策略。