It is of great importance to develop highly efficient and stable Pt‐free catalysts for electrochemical hydrogen generation from water electrolysis. Here, monodisperse 7.5 nm copper‐doped ruthenium hollow nanoparticles (NPs) with abundant defects and amorphous/crystalline hetero‐phases were prepared and employed as efficient hydrogen evolution electrocatalysts in alkaline electrolyte. Specifically, these NPs only require a low overpotential of 25 mV to achieve a current density of 10 mA cm⁻² in 1.0 M KOH and show acceptable stability after 2000 potential cycles, which represents one of the best Ru‐based electrocatalysts for hydrogen evolution. Mechanism analysis indicates that Cu incorporation can modify the electronic structure of Ru shell, thereby optimizing the energy barrier for water adsorption and dissociation processes or H adsorption/desorption. Cu doping paired with the defect‐rich and highly open hollow structure of the NPs greatly enhances hydrogen evolution activity.

中文翻译：

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碱性电解质中高效氢析出电催化的富缺陷铜掺杂钌空心纳米粒子。

开发高效，稳定的无铂催化剂用于水电解产生电化学氢至关重要。在这里，制备了具有丰富缺陷和非晶/结晶异相的单分散7.5 nm铜掺杂钌空心纳米粒子（NPs），并将其用作碱性电解质中的高效氢析出电催化剂。具体而言，这些NP仅需要25 mV的低超电势即可实现10 mA cm ^-2的电流密度在1.0 M KOH中，在2000个电位循环后显示出可接受的稳定性，这是用于析氢的最佳Ru基电催化剂之一。机理分析表明，Cu的掺入可以改变Ru壳的电子结构，从而优化水吸附和离解过程或H吸附/解吸的能垒。铜掺杂与NPs的缺陷丰富且高度开放的空心结构配对，大大增强了析氢活性。