Developing highly efficient and robust nonprecious metal-based electrocatalysts for overall fresh/sea water electrolysis for hydrogen production remains a major challenge for the hydrogen economy. In this study, a novel approach utilizing a one-step rapid electrodeposition technique was employed to fabricate amorphous bimetallic nickel–iron–phosphorus (NiFeP) nanosheets with tunable compositions on nickel phosphorus (NiP) microspheres. The unique amorphous structure and the capability to adjust the composition of the NiFeP nanosheets were crucial for enhancing the electronic structure and increasing the number of active sites on the catalyst. The seamless integration and self-supporting nature of the NiFeP/NiP on nickel foam significantly enhanced mass transport and minimized electrical resistance during the electrocatalytic process. Moreover, the superior corrosion resistance of the amorphous NiFeP/NiP contributed to its outstanding stability over prolonged periods. When optimized, the NiFeP/NiP with 25% iron content demonstrated low overpotentials of 241.8 and 273.7 mV for the OER at current densities of 10 and 100 mA cm⁻², respectively, in alkaline freshwater. Additionally, NiFeP/NiP with 10% iron content exhibited low overpotentials of 69.5 and 127.6 mV for the hydrogen evolution reaction (HER) at the same current densities in the same medium. In alkaline seawater, the optimized configurations for OER and HER showed overpotentials at corresponding current densities, further confirming the catalysts’ efficiency under varying conditions. When employed in an electrolyzer for splitting alkaline freshwater or seawater, the combination of NiFeP/NiP electrodes with 10% and 25% iron content operated at remarkably low voltages of 1.55 and 1.62 V to achieve a current density of 10 mA cm⁻², respectively. This performance was stable over 500 hours, surpassing that of nearly all previously reported non-noble metal electrocatalysts and even the benchmark platinum/carbon and ruthenium dioxide coupled electrodes for both freshwater and seawater electrolysis. This research introduces a straightforward and expedient method for crafting non-noble metal electrocatalysts with modifiable composition and electronic modulation, yielding highly active and durable catalysts for alkaline water splitting.

中文翻译：

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自支撑非晶 Ni-Fe-P 纳米片装饰 NiP 微球的可调节成分，可实现高效稳定的整体碱性淡水/海水分解

开发高效且强大的非贵金属基电催化剂用于整体淡水/海水电解制氢仍然是氢经济的主要挑战。在这项研究中，采用了一种利用一步快速电沉积技术的新方法，在镍磷（NiP）微球上制造成分可调的非晶双金属镍铁磷（NiFeP）纳米片。 NiFeP 纳米片独特的非晶结构和调整成分的能力对于增强电子结构和增加催化剂上的活性位点数量至关重要。泡沫镍上的 NiFeP/NiP 的无缝集成和自支撑性质显着增强了电催化过程中的传质并最小化了电阻。此外，非晶态 NiFeP/NiP 优异的耐腐蚀性使其具有出色的长期稳定性。经过优化后，铁含量为 25% 的 NiFeP/NiP 在碱性淡水中，在电流密度为 10 和 100 mA cm ^-2时，OER 的过电势分别为 241.8 和 273.7 mV。此外，铁含量为 10% 的 NiFeP/NiP 在相同介质中相同电流密度下的析氢反应 (HER) 表现出 69.5 和 127.6 mV 的低过电势。在碱性海水中，OER 和 HER 的优化配置在相应的电流密度下表现出过电势，进一步证实了催化剂在不同条件下的效率。当用于分解碱性淡水或海水的电解槽中时，铁含量为10%和25%的NiFeP/NiP电极组合在1.55和1.62 V的极低电压下运行，分别实现10 mA cm -2 的电流^密度。该性能在 500 小时内保持稳定，超过了几乎所有先前报道的非贵金属电催化剂，甚至超过了用于淡水和海水电解的基准铂/碳和二氧化钌耦合电极。这项研究介绍了一种简单而便捷的方法来制作具有可改变成分和电子调制的非贵金属电催化剂，从而产生用于碱性水分解的高活性和耐用的催化剂。