Rational design and construction of bifunctional electrocatalysts with excellent activity and durability is imperative for water splitting. The regulation of the local electronic structure of the active metal sites in polymetallic composites provides a basic idea. Herein, the ultrathin bimetallic molybdate nanosheets are evenly deposited on the CuO_x hollow nanotubes on the copper foam substrate to form a hierarchical heterostructure, which can be used as an efficient bifunctional electrocatalyst for overall water splitting. Experimental results prove that the introduction of Ni to form a double metal salt molybdate and CuO_x heterostructure design can be optimized by Co cation as best electronic structure of electric catalytic activity center, and can effectively promote the generation of CoOOH active phase at the same time, so that can skillfully optimize the binding strength between the Co site and the oxygen-containing intermediate, and enhancing catalytic activity. When it is used in the overall water splitting of a double-electrode alkaline electrolytic cell, the cell voltage of CoNiMoO₄-21/CuO_x/CF is 1.532 V at 50 mA cm^−2, far exceeding most of the reported conventional bifunctional electrocatalyst. This work has contributed to understanding the central active sites of polymetallic composites and has provided a useful value for the design of efficient electrocatalysts.

中文翻译：

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超薄镍钴双金属钼酸盐纳米片涂层 CuOx 纳米管：活性位点的异质结构和双金属协同优化以实现高效的整体水分解

合理设计和构建具有优异活性和耐久性的双功能电催化剂对于水分解势在必行。多金属复合材料中活性金属位点的局部电子结构的调节提供了一个基本思路。在此，超薄双金属钼酸盐纳米片均匀沉积在泡沫铜基材上的CuO _x空心纳米管上，形成分层异质结构，可作为高效的双功能电催化剂用于整体水分解。实验结果证明，Ni的引入形成了钼酸盐和CuO _x的双金属盐异质结构设计可以通过Co阳离子作为电催化活性中心的最佳电子结构进行优化，同时可以有效促进CoOOH活性相的生成，从而可以巧妙地优化Co位点与含氧位点之间的结合强度中间体，提高催化活性。用于双电极碱性电解槽的整体水分解时，CoNiMoO ₄ -21/CuO _x /CF的电池电压在 50 mA cm ^{∼ 2 时}为 1.532 V ，远远超过大多数报道的常规双功能电催化剂。这项工作有助于了解多金属复合材料的中心活性位点，并为设计高效电催化剂提供了有用的价值。