ABSTRACT Nowadays, it is still a great challenge to explore highly active and stable noble-metal-free electrocatalysts for sustainable overall water splitting. In this work, a novel electrode of three-dimensional network-like Ni2P-MoS2 heterogeneous nanosheet arrays on carbon cloth (HNSAs/CC) was designed and fabricated by a two-step strategy. Benefiting from the unique 3D hierarchical architecture, large specific surface area, synergistic effects between Ni2P and MoS2, and the support of highly conductive carbon cloth, the obtained electrode exhibits superior electrocatalytic activity for hydrogen and oxygen evolution reaction (HER and OER) in 1 mol·L-1 KOH aqueous solution with extremely low overpotentials of 78 and 258 mV respectively to deliver a current density of 10 mA·cm-2. The electrocatalytic system assembled with the obtained Ni2P-MoS2 HNSAs/CC sample as both anode and cathode for overall water splitting requires an impressively low onset potential of only 1.574 V to attain a current density of 10 mA·cm-2 and displays an excellent long-term stability. According to density functional theory calculation, the enhanced water splitting activity could be mainly attributed to the modified interfacial electronic structures and the enhanced thermoneutral adsorption of absorbates on the surface of Ni2P (110) - MoS2 (100) heterostructure. The calculated theoretical overpotentials for HER and OER based on Ni2P (110) - MoS2 (100) heterostructure are 0.019 and 0.279 V, respectively. The facile synthesis method and insights into the HER and OER active interfaces reported here will advance the development of high-performance bifunctional overall water splitting electrocatalysts.

中文翻译：

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用于高效电化学整体水分解的新型三维 Ni2P-MoS2 异质纳米片阵列

摘要 目前，探索高活性且稳定的无贵金属电催化剂用于可持续的整体水分解仍然是一个巨大的挑战。在这项工作中，通过两步策略设计和制造了一种新型的碳布上的三维网络状 Ni2P-MoS2 异质纳米片阵列电极（HNSAs/CC）。得益于独特的 3D 分层结构、大比表面积、Ni2P 和 MoS2 之间的协同效应以及高导电碳布的支撑，所获得的电极对 1 mol 的氢和氧析出反应（HER 和 OER）表现出优异的电催化活性·L-1 KOH水溶液具有分别为78 mV和258 mV的极低过电位，可提供10 mA·cm-2的电流密度。以所获得的 Ni2P-MoS2 HNSAs/CC 样品作为阳极和阴极进行整体水分解的电催化系统需要仅 1.574 V 的低起始电位才能获得 10 mA·cm-2 的电流密度，并显示出优异的长- 长期稳定性。根据密度泛函理论计算，增强的水分解活性主要归因于界面电子结构的改进和Ni2P（110）-MoS2（100）异质结构表面吸收物的热中性吸附增强。基于 Ni2P (110) - MoS2 (100) 异质结构的 HER 和 OER 计算的理论过电位分别为 0.019 和 0.279 V。