Creating durable and efficient multifunctional electrocatalysts capable of high current densities at low applied potentials is crucial for widespread industrial use in hydrogen production. Herein, a Co–Ni–Fe–Cu–Mo (oxy)hydroxide electrocatalyst with abundant grain boundaries on nickel foam using a scalable coating method followed by chemical precipitation is synthesized. This technique efficiently organizes hierarchical Co–Ni–Fe–Cu–Mo (oxy)hydroxide nanoparticles within ultrafine crystalline regions (<4 nm), enriched with numerous grain boundaries, enhancing catalytic site density and facilitating charge and mass transfer. The resulting catalyst, structured into nanosheets enriched with grain boundaries, exhibits superior electrocatalytic activity. It achieves a reduced overpotential of 199 mV at 10 mA cm² current density with a Tafel slope of 48.8 mV dec¹ in a 1 m KOH solution, maintaining stability over 72 h. Advanced analytical techniques reveal that incorporating high-valency copper and molybdenum elements significantly enhances lattice oxygen activation, attributed to weakened metal–oxygen bonds facilitating the lattice oxygen mechanism (LOM). Synchrotron radiation studies confirm a synergistic interaction among constituent elements. Furthermore, the developed high-entropy electrode demonstrates exceptional long-term stability under high current density in alkaline environments, showcasing the effectiveness of high-entropy strategies in advancing electrocatalytic materials for energy-related applications.

中文翻译：

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高价金属驱动电子调制高熵Co-Ni-Fe-Cu-Mo（氧）氢氧化物作为优异多功能电催化剂的合理设计策略


创造能够在低施加电位下实现高电流密度的耐用且高效的多功能电催化剂对于氢生产的广泛工业应用至关重要。在此，使用可扩展的涂覆方法和化学沉淀合成了在泡沫镍上具有丰富晶界的Co-Ni-Fe-Cu-Mo（氧）氢氧化物电催化剂。该技术在超细结晶区域（<4 nm）内有效地组织分层的Co-Ni-Fe-Cu-Mo（氧）氢氧化物纳米颗粒，富含大量晶界，提高催化位点密度并促进电荷和质量传递。所得催化剂被构造成富含晶界的纳米片，表现出优异的电催化活性。它在 10 mA cm ² 电流密度下实现了 199 mV 的降低过电位，在 1 m KOH 溶液中塔菲尔斜率为 48.8 mV dec ¹ ，并在 72 小时内保持稳定性。先进的分析技术表明，掺入高价铜和钼元素可显着增强晶格氧活化，这是由于金属-氧键减弱，促进了晶格氧机制（LOM）。同步辐射研究证实了组成元素之间的协同相互作用。此外，所开发的高熵电极在碱性环境中的高电流密度下表现出优异的长期稳定性，展示了高熵策略在推进能源相关应用的电催化材料方面的有效性。