Earth-abundant, efficient and durable electrocatalysts for water splitting are vitally important for a sustainable energy system. Here we report the rational design of hollow Mo-doped CoP (Mo-CoP) nanoarrays, which simultaneously combine electronic structure modification through doping with a high density of reaction sites through nanostructuring. With this strategy the Mo-CoP arrays give significantly improved hydrogen evolution reaction (HER) performance, and also, when in situ transformed into Mo-doped CoOOH (Mo-CoOOH) arrays, excellent activity towards the oxygen evolution reaction (OER) is obtained. The origin of the improvement is determined by atomic-resolution imaging combined with density functional theory (DFT). An electrolyzer using Mo-CoP and Mo-CoOOH can be powered by a single AA battery (~1.5 V), and maintains a stable water-splitting current for 20 h, superior to most reported electrocatalysts in alkaline media, offering great promise for practical applications.

地球上充裕，高效和耐用的用于水分解的电催化剂对于可持续能源系统至关重要。在这里，我们报告了中空Mo掺杂CoP（Mo-CoP）纳米阵列的合理设计，该阵列同时结合了通过掺杂进行的电子结构修饰和通过纳米结构进行的高反应位密度。通过这种策略，Mo-CoP阵列可显着改善氢气析出反应（HER）的性能，以及在原位使用时的性能。如果将其转变成掺杂Mo的CoOOH（Mo-CoOOH）阵列，则可获得出色的抗氧析出反应（OER）活性。改进的源头是通过原子分辨率成像结合密度泛函理论（DFT）来确定的。使用Mo-CoP和Mo-CoOOH的电解器可以由一个AA电池（〜1.5 V）供电，并能在20小时内保持稳定的水分解电流，优于大多数报道的碱性介质中的电催化剂，为实际应用提供了广阔前景应用程序。