High-entropy materials are new-fashioned electrocatalysts due to their interesting “cocktail effect”. However, it is still a great challenge to synthesize single-crystal high-entropy nanomaterials such as (oxy)hydroxides due to the different crystal growth mode for different elements. Herein, we design a dynamic crystal growth strategy by multi-cation exchange to fabricate single-crystal high-entropy (oxy)hydroxides nanosheets. Nanoporous morphology can be achieved by incorporating Al ion into the multicomponent (oxy)hydroxides system after a reversible Al insertion-dissolution process. When adopted as potential electrocatalysts for oxygen evolution reaction (OER), we find that the seven-component ZnVNiCoFeAlRu-OHs single-crystal nanoporous nanosheets display a significantly improved OER performance with a low overpotential of 229 mV at 10 mA cm⁻² and a shallow Tafel slope of 39.3 mV dec⁻¹. Both XPS and DFT calculation reveal that Ru acted an electron dedicator could effectively moderate the overall electronic structures for better OER performance. This work develops an entropy and enthalpy driven multi-cation exchange strategy for synthesizing a library of single-crystal high-entropy (oxy)hydroxides for various applications.

高熵材料因其有趣的“鸡尾酒效应”而成为新型电催化剂。然而，由于不同元素的晶体生长方式不同，合成（氧）氢氧化物等单晶高熵纳米材料仍然是一个巨大的挑战。在此，我们通过多阳离子交换设计了一种动态晶体生长策略，以制造单晶高熵（氧）氢氧化物纳米片。在可逆的 Al 插入-溶解过程后，通过将 Al 离子结合到多组分（氧）氢氧化物系统中，可以实现纳米多孔形态。当用作析氧反应 (OER) 的潜在电催化剂时，我们发现七组分 ZnVNiCoFeAlRu-OHs 单晶纳米多孔纳米片显示出显着改善的 OER 性能，在 10 mA cm 时具有 229 mV 的低过电位^{-2和 39.3 mV dec -1}的浅 Tafel 斜率。XPS 和 DFT 计算均表明 Ru 作为电子奉献者可以有效调节整体电子结构以获得更好的 OER 性能。这项工作开发了一种熵和焓驱动的多阳离子交换策略，用于合成用于各种应用的单晶高熵（氧）氢氧化物库。