Orderly assembled supernanosheets (ASNSs), integrating the architectural features of subunit NSs, 2D subnanometer interlayer spacings, and multiple electroactive sites, can remarkably expand the functionality and stability of 2D multimetallic nanomaterials. Here, we report a versatile template-directed strategy for synthesizing multimetallic ASNSs. As a proof-of-concept, ternary Pd₄₄Pt₃₀Ir₂₆ ASNSs are elaborately synthesized and applied as robust bifunctional electrocatalysts toward overall water splitting. The products are mesocrystalline 2D superstructures derived from lamellar stacking of ultrathin Pd–Pt–Ir NSs. During electrocatalysis, the multilayered superstructures can locally concentrate reactants within the parallel subnanometer interlayer spacings and essentially intensify the morphological stability. Featured with electronically modulated Pt–IrO_x dual active sites, the products exhibit high efficiency and durable bifunctional electrocatalytic activity for overall water splitting in 1.0 M KOH, presenting 46 and 92 mV lower overpotential than the state-of-the-art Pt/C and Ir/C for hydrogen evolution and oxygen evolution reactions, respectively. Significantly, they can realize stable H₂ production at a large current of 500 mA in an anion exchange membrane electrolyzer. This work fully proves that the integration of an ordered 2D superstructure and electronic-modulated multiple reactive sites has broad prospects for advanced electrocatalysts.

中文翻译：

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具有亚纳米层间距的二维组装 Pd-Pt-Ir 超纳米片实现高效和持久的水分解

有序组装的超纳米片（ASNSs）结合了亚基NSs的结构特征、二维亚纳米层间距和多个电活性位点，可以显着扩展二维多金属纳米材料的功能性和稳定性。在这里，我们报告了一种用于合成多金属 ASNS 的通用模板导向策略。作为概念验证，三元 Pd ₄₄ Pt ₃₀ Ir ₂₆ASNS 被精心合成并用作稳健的双功能电催化剂，用于整体水分解。这些产品是由超薄 Pd-Pt-Ir NSs 的层状堆叠衍生的介晶二维超结构。在电催化过程中，多层超结构可以将反应物局部集中在平行的亚纳米层间距内，并从本质上增强形态稳定性。该产品具有电子调制的 Pt-IrO _x双活性位点，在 1.0 M KOH 中对整体水分解表现出高效和持久的双功能电催化活性，其过电位比最先进的 Pt/C 低 46 和 92 mV和 Ir/C 分别用于析氢和析氧反应。重要的是，它们可以实现稳定的 H₂在阴离子交换膜电解槽中以 500 mA 的大电流生产。这项工作充分证明了有序的二维超结构和电子调制的多个反应位点的集成对于先进电催化剂具有广阔的前景。