Rational design and construction of high-efficiency bifunctional catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for large-scale hydrogen production by water splitting. Herein, by a self-sacrificial template method, Fe–Co–P multi-heterostructure arrays consisting of CoP, Co₂P and FeP are built for water splitting. Such multi-heterostructures adjust the local electronic structure and then improve adsorption of reaction intermediates on active sites, which is further proved through density functional theory (DFT) calculations. Thus, without noble metals, the as-prepared Fe–Co–P multi-heterostructure catalyst exhibits very high catalytic performance, which only needs 227 and 87 mV to reach a current density of 20 and 10 mA cm⁻² for the OER and HER, respectively, better than most of the related catalysts reported so far. Moreover, when used in alkaline electrolyzers, it delivers a current density of 10 mA cm⁻² at a cell voltage of 1.55 V, superior to commercial Pt-group electrodes (1.59 V). Our work offers a novel approach to rationally design catalysts toward water splitting.

中文翻译：

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用于高效电催化水分解的 Fe-Co-P 多异质结构阵列

用于析氢反应（HER）和析氧反应（OER）的高效双功能催化剂的合理设计和构建对于水分解大规模制氢至关重要。在此，通过自牺牲模板方法，构建了由 CoP、Co ₂ P 和 FeP组成的 Fe-Co-P 多异质结构阵列用于水分解。这种多异质结构调整了局部电子结构，然后改善了反应中间体在活性位点上的吸附，这通过密度泛函理论（DFT）计算得到了进一步证明。因此，在没有贵金属的情况下，所制备的 Fe-Co-P 多异质结构催化剂表现出非常高的催化性能，仅需 227 和 87 mV 即可达到 20 和 10 mA cm ^-2的电流密度对于 OER 和 HER，分别优于迄今为止报道的大多数相关催化剂。此外，当用于碱性电解槽时，它在 1.55 V 的电池电压下提供 10 mA cm ^-2的电流密度，优于商用铂族电极 (1.59 V)。我们的工作提供了一种合理设计水分解催化剂的新方法。