The design and development of highly active electrocatalysts for the hydrogen evolution reaction (HER) in alkaline media is of significant importance. In this communication, we report the direct growth of an ultralow-Pt-content (Pt content: 5.1 wt%) Ni(OH)₂–PtO₂ hybrid nanosheet array on a Ti mesh (Ni(OH)₂–PtO₂ NS/Ti), carried out by hydrothermal treatment of a Ni(OH)₂ nanosheet array on a Ti mesh (Ni(OH)₂ NS/Ti) in the presence of [PtCl₆]²⁻. When used as a 3D catalyst electrode for the HER, the resulting Ni(OH)₂–PtO₂ NS/Ti exhibits superior activity with the need of an overpotential of only 31.4 mV to deliver a geometrical catalytic current density of 4 mA cm⁻² in 0.1 M KOH. Remarkably, this catalyst also shows strong long-term electrochemical durability for at least 100 h with a faradaic efficiency close to 100%. Density functional theory calculations reveal that the Ni(OH)₂/PtO₂ interface can promote the kinetics of H₂O dissociation and tune the hydrogen adsorption free energy to a more moderate value, thereby promoting the HER.

中文翻译：

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具有超低Pt负载 的Ni（OH）₂ -PtO ₂杂化纳米片阵列，可有效且持久地释放出碱性氢†

在碱性介质中设计和开发用于氢释放反应（HER）的高活性电催化剂非常重要。在本交流中，我们报告了在Ti网格（Ni（OH）₂ –PtO ₂ NS /上，超低Pt含量（Pt含量：5.1 wt％）Ni（OH）₂ –PtO ₂杂化纳米片阵列的直接生长。Ti），在[PtCl ₆ ] ^2-的存在下，通过对Ti网孔（Ni（OH）₂ NS / Ti）上的Ni（OH）₂纳米片阵列进行水热处理来进行。当用作HER的3D催化剂电极时，所得的Ni（OH）₂ -PtO ₂NS / Ti表现出优异的活性，仅需31.4 mV的超电势即可在0.1 M KOH中提供4 mA cm ^-2的几何催化电流密度。值得注意的是，该催化剂还显示出至少100小时的强长期电化学耐久性，法拉第效率接近100％。密度泛函理论计算表明，Ni（OH）₂ / PtO ₂界面可以促进H ₂ O离解的动力学，并将氢吸附自由能调节至更适中的值，从而促进HER。