The water electrolysis for commercial hydrogen production is dependent on efficient and economical electrocatalysts toward both half reactions of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). In this work, an Fe-doped Co₁₁(HPO₃)₈(OH)₆ nanosheets array was fabricated on Ni foam via a one-step liquid-phase approach in the solvents of deionized water and isopropyl alcohol as such a bifunctional electrocatalyst. The different proton acceptors of hydroxyl and phosphite in Co₁₁(HPO₃)₈(OH)₆ nanosheets expedited the proton and electron transfer. The Fe dopant in Co₁₁(HPO₃)₈(OH)₆ adjusted the electronic structure of Co₁₁(HPO₃)₈(OH)₆, which significantly increased the hydrophilicity, conductivity, and active surface area. The density functional theory (DFT) calculations showed the Gibbs free energy of OER intermediates and H* adsorption energy in HER process were lowered, while the density of states (DOS) in the d-band center was increased by Fe doping, suggesting that Fe-doped Co₁₁(HPO₃)₈(OH)₆ is more active towards OER and HER processes. As a result, the optimized Fe_11.7%-Co₁₁(HPO₃)₈(OH)₆ shows outstanding activity, durability and robust structural stability toward both OER and HER in 1 M KOH electrolyte. For OER, it outputs 20 mA cm⁻² merely at an overpotential of 206 mV. Benefited from monolithically integrated nanosheets array structure on Ni foam, it can stably drive 500 mA cm⁻² at a fairly low overpotential of 268 mV. For HER, a low overpotential of 102 mV for 10 mA cm⁻² and 263 mV for 500 mA cm⁻² are acquired on Fe_11.7%-Co₁₁(HPO₃)₈(OH)₆. This offers a water-alkali electrolyzer by two Fe_11.7%-Co₁₁(HPO₃)₈(OH)₆ electrodes implements a low cell voltage of 1.494 V for 10 mA cm⁻², and 1.772 V for 500 mA cm⁻² toward overall water electrolysis with striking stability. This work opens a promising avenue in exploring highly active and stable catalysts by transition metal phosphites with suitable element doping toward scale-up water electrolysis.

用于工业制氢的水电解取决于高效且经济的电催化剂，以同时进行氧气逸出反应（OER）和氢气逸出反应（HER）的半反应。在这项工作中，在去离子水和异丙醇作为双功能电催化剂的溶剂中，通过一步液相方法，在镍泡沫上制备了掺铁的Co ₁₁（HPO ₃）₈（OH）₆纳米片阵列。Co ₁₁（HPO ₃）₈（OH）₆纳米片中羟基和亚磷酸酯的不同质子受体加快了质子和电子的转移。Co ₁₁（HPO ₃）₈（OH）₆调节了Co ₁₁（HPO ₃）₈（OH）₆的电子结构，从而显着提高了亲水性，导电性和活性表面积。密度泛函理论（DFT）计算表明，铁掺杂降低了OER中间体的吉布斯自由能和H *吸附过程中的H *吸附能，而d波段中心的态密度（DOS）增加了，这表明铁掺杂的Co ₁₁（HPO ₃）₈（OH）₆对OER和HER过程更具活性。结果，优化的Fe _11.7％ -Co ₁₁（HPO ₃）₈（OH）₆在1 M KOH电解质中对OER和HER均显示出出色的活性，耐久性和坚固的结构稳定性。对于OER，仅在206 mV的超电势下输出20 mA cm ^-2。得益于镍泡沫上的单片集成纳米片阵列结构，它可以 在268 mV的相当低的超电势下稳定地驱动500 mA cm ^-2。对于HER，在Fe _11.7％ -Co ₁₁（HPO ₃）₈（OH）₆上获得了102 mV的低过电势（10 mA cm ^-2）和263 mV的500 mA cm ^-2。这提供了两种Fe _11.7％ -Co的水碱电解槽₁₁（HPO ₃）₈（OH）₆电极可实现10 mA cm ^-2的低电池电压1.494 V和500 mA cm ^-2的1.772 V低电池电压，具有显着的稳定性。这项工作为通过过渡金属亚磷酸酯探索高活性和稳定的催化剂开辟了一条有希望的途径，其中适当的元素掺杂朝向水电解。