It is urgent to explore cost-effective, high-efficiency, and durable electrocatalysts for electrochemical water splitting due to the rapidly increasing energy consumption. In this work, we successfully synthesize Ca-doped CuCoO₂ nanosheets (CCCO-P NSs) with different Ca²⁺ dopants (such as 3, 5, and 10 atom %) by a surfactant-modified hydrothermal reaction with polyvinylpyrrolidone (PVP) addition. The oxygen evolution reaction (OER) performances of these CCCO-P NSs in 1.0 M KOH are investigated. An optimal nickel foam supported CCCO-P2 NSs (Ni@CCCO-P2, 5 atom % Ca-doped) electrode requires low overpotential of 470 mV to afford the current density of 10 mA cm^–2 and small Tafel slope of 96.5 mV dec^–1. Furthermore, the Ni@CCCO-P2 electrode displays outstanding long-term stability during the galvanostatic OER electrolysis for 18 h with a little degradation of 32 mV. The improvement of OER performances for CCCO-P2 NSs could be attributed to their higher active surface area, more active sites (Co vacancies defect and Co³⁺/Co⁴⁺ redox pairs), and higher electrical conductivity. This work highlights the joint effect of surfactant and Ca doping for preparing CuCoO₂ with nanosheet-like morphology and porous crystal structure, which is favorable for enhancing their OER performance.

中文翻译：

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表面活性剂修饰的水热法合成具有大量活性位点的Ca掺杂CuCoO2纳米片，可增强电催化氧的释放。

由于迅速增加的能耗，迫切需要探索经济有效，高效耐用的电化学分解水用电催化剂。在这项工作中，我们通过聚乙烯吡咯烷酮（PVP）添加的表面活性剂改性水热反应成功地合成了具有不同Ca ²⁺掺杂剂（例如3、5和10原子％）的Ca掺杂CuCoO ₂纳米片（CCCO-P NSs）。。研究了这些CCCO-P NS在1.0 M KOH中的析氧反应（OER）性能。最佳的支持镍泡沫的CCCO-P2 NSs（Ni @ CCCO-P2，5原子％Ca掺杂）电极需要470 mV的低过电势，才能提供10 mA cm ^–2的电流密度和96.5 mV dec的小Tafel斜率^{– 1个}。此外，Ni @ CCCO-P2电极在恒电流OER电解18小时期间表现出出色的长期稳定性，但降解很少，仅为32 mV。CCCO-P2 NSs的OER性能的提高可以归因于其较高的活性表面积，更多的活性位点（Co空位缺陷和Co ³⁺ / Co ⁴⁺氧化还原对）和更高的电导率。这项工作突出了表面活性剂和Ca掺杂对制备具有纳米片状形态和多孔晶体结构的CuCoO ₂的联合作用，有利于增强其OER性能。