Abstract The preparation of stable and efficient thin films with excellent energy storage and conversion capabilities has attracted great attention in the field of supercapacitors and electrocatalysis. Herein, hierarchical nanosheets-based ternary CoNiFe layered double hydroxide (LDH) thin films are prepared via an inexpensive and facile electrodeposition method. The structural, morphological, and electrochemical properties of films are systematically studied and compared with their binary counterparts. As prepared CoNiFe LDH shows a maximum specific capacity of 360 C g-1 at the current density of 0.4 A g-1 with a capacity retention of 51% even at the higher current density of 10 A g-1. Moreover, it shows excellent cyclic stability of 84% after 2000 cycles. As an electrocatalyst, CoNiFe LDH demonstrates an excellent performance in OER, affording an overpotential of 196 mV at the current density of 10 mA cm-2 with a Tafel slope value of 49 mV dec-1. Also, it depicts excellent catalytic stability with stable operation for over 10 h. Thus, ternary CoNiFe LDH thin film can be used as a promising electrode material for both electrochemical energy storage and catalysis.

中文翻译：

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用于超级电容器和析氧反应的三元 CoNiFe 层状双氢氧化物的分层纳米片

摘要 制备稳定高效且具有优异储能和转换能力的薄膜在超级电容器和电催化领域引起了广泛关注。在此，基于分层纳米片的三元 CoNiFe 层状双氢氧化物 (LDH) 薄膜是通过廉价且简便的电沉积方法制备的。系统地研究了薄膜的结构、形态和电化学特性，并与其二元对应物进行了比较。所制备的 CoNiFe LDH 在 0.4 A g-1 的电流密度下显示出 360 C g-1 的最大比容量，即使在 10 A g-1 的较高电流密度下也具有 51% 的容量保持率。此外，它在 2000 次循环后显示出 84% 的优异循环稳定性。作为电催化剂，CoNiFe LDH 在 OER 方面表现出优异的性能，在 10 mA cm-2 的电流密度下提供 196 mV 的过电位，Tafel 斜率为 49 mV dec-1。此外，它还表现出优异的催化稳定性，可稳定运行超过 10 小时。因此，三元 CoNiFe LDH 薄膜可用作电化学储能和催化的有前途的电极材料。