Fabricating a functional heterogeneous interface to enhance catalytic performance is quite significant for developing high-efficiency electrocatalysts. Herein, a coral-like nickel phosphide@cerium oxide (Ni₂P@CeO₂) hybrid nanoarray on nickel foam was designed via selective-phosphorization of nickel hydroxide@cerium oxide (Ni(OH)₂@CeO₂). Benefiting from CeO₂ as the “electron pump,” it leads to electron transfer from Ni₂P to the CeO₂ side, and induces electron redistribution in the interface boundary, thereby optimizing the H* adsorption free energy in the hydrogen evolution reaction (HER) process. As hypothesized, the water molecules will preferentially adsorb on the CeO₂ side due to its better affinity for oxygen-containing species, and will readily break down into OH* and H* at a lower energy barrier. Subsequently, benefiting from the lower H* adsorption free energy of P sites, the generated H* will migrate to the Ni₂P side through the spillover process. Contributing to the synergistic effect of double-active sites, the Ni₂P@CeO₂/NF electrode exhibits brilliant catalytic performance for HER with 62 mV to attain 10 mA/cm² and exceptional durability over 100 h in alkaline solution at ~ 100 mA/cm². Meanwhile, attributing to the similar interface electron redistribution effect, the precursor Ni(OH)₂@CeO₂/NF likewise displays excellent oxygen evolution reaction (OER) electrocatalytic performance, which only requires 229 mV to arrive at 10 mA/cm², even better than benchmark ruthenium dioxide (RuO₂). Hence, the assembled Ni(OH)₂@CeO₂/NF||Ni₂P@CeO₂/NF system only needs 1.53 V to achieve 10 mA/cm² in alkaline solution. Moreover, the electrolyzer also presents brilliant electrocatalytic activity and stability in alkaline natural seawater electrolyte with higher reserves on earth.

Graphical Abstract

“Electrons pump” effect of CeO₂ ensures that interface-engineered Ni₂P@CeO₂ hybrid nanoarrays prepared via selective-phosphorization treatment present superior HER catalytic performance

中文翻译：

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构建界面工程珊瑚状磷化镍@氧化铈混合纳米阵列以提高碱性水/海水电解质中的电催化析氢性能

制造功能性异质界面以增强催化性能对于开发高效电催化剂具有重要意义。本文通过氢氧化镍@氧化铈（Ni (OH) ₂ @CeO ₂）的选择性磷化设计了泡沫镍上的珊瑚状磷化镍@氧化铈（Ni ₂ P @CeO ₂）杂化纳米阵列。受益于 CeO ₂作为“电子泵”，它导致电子从 Ni ₂ P 转移到 CeO ₂侧，并诱导界面边界中的电子重新分布，从而优化析氢反应（HER）过程中的H*吸附自由能。正如假设的，由于水分子对含氧物质有更好的亲和力，水分子将优先吸附在CeO _{2侧，并且在较低能垒下很容易分解成OH*和H*。}随后，受益于P位较低的H*吸附自由能，生成的H*将通过溢出过程迁移到Ni _{2 P侧。}得益于双活性位点的协同效应，Ni ₂ P@CeO ₂ /NF电极对HER表现出出色的催化性能，在62 mV下即可达到10 mA/cm ²在约 100 mA/cm ²的碱性溶液中具有超过 100 小时的出色耐久性。同时，由于相似的界面电子重新分布效应，前驱体Ni(OH) ₂ @CeO ₂ /NF同样表现出优异的析氧反应(OER)电催化性能，仅需229 mV即可达到10 mA/cm ²，甚至优于基准二氧化钌 (RuO ₂ )。因此，组装的Ni(OH) ₂ @CeO ₂ /NF || Ni ₂ P@CeO ₂ /NF系统仅需1.53 V即可实现10 mA/cm ²在碱性溶液中。此外，该电解槽在地球储量较高的碱性天然海水电解液中也表现出优异的电催化活性和稳定性。

图形概要

_{CeO 2}的“电子泵”效应确保通过选择性磷化处理制备的界面工程Ni ₂ P@CeO _{2杂化纳米阵列具有优异的HER催化性能}