On the way to energy-efficient and cost-effective hydrogen production by electrochemical or photoelectrochemical water splitting, it is of primary importance to develop highly active and durable water oxidation electrocatalysts based on earth-abundant elements. Here we report a highly active, robust, cheap, and facilely fabricated O₂-evolving catalyst on a Cu foil, NiB_0.45-250/Cu, which forms a NiB_0.45/NiO_x core-shell heterostructured nanoparticulate film during anodic electrolysis. The performance of NiB_0.45-250/Cu, to produce 10 mA cm⁻² at 296 mV overpotential in 1 M KOH over 60 h, is at par with the best efficiency of earth-abundant electrocatalysts reported to date and surpasses that of IrO₂-loaded copper electrode under identical conditions. Experimental evidence and theoretical calculations reveal the correlations of B/Ni atomic ratio and annealing temperature with the morphology, surface microtexture, electrochemical active surface area, and electrical conductivity of NiB_x films. Optimal combination of these factors can evidently enhance the catalytic activity of nickel boride electrocatalysts.

在通过电化学或光电化学水分解生产节能且具有成本效益的氢的方法中，开发基于土壤丰富元素的高活性和持久性水氧化电催化剂至关重要。在这里，我们报告了在铜箔NiB _0.45 -250 / Cu上形成的高活性，坚固，廉价且易于制造的O ₂析出催化剂，该阳极箔在阳极电解过程中形成NiB _0.45 / NiO _x核-壳异质结构纳米颗粒膜。NiB _0.45 -250 / Cu产生10 mA cm ^-2的性能在60小时内以1 M KOH在296 mV的超电势下，达到了迄今报道的地球上最富电催化剂的最佳效率，并且在相同条件下超过了负载IrO _2的铜电极的效率。实验证据和理论计算揭示了B / Ni原子比和退火温度与NiB _x膜的形貌，表面微观结构，电化学活性表面积和电导率之间的相关性。这些因素的最佳组合可以明显增强硼化镍电催化剂的催化活性。