Rational design and preparation of advanced electrocatalysts for the oxygen evolution reaction (OER) are highly desirable, where various strategies have been applied to enhance the electrocatalytic activities, such as developing nanostructures, facet control, and creating oxygen vacancies. Herein, we have successfully integrated multiple strategies into one catalytic system for further enhancing the OER performance. A series of hollow Co₃O₄ dodecahedrons with controlled crystal orientation and oxygen vacancies were prepared by using ZIF-67 as a precursor and adjusting the atmosphere during calcination. Hollow Co₃O₄ dodecahedrons with both controlled exposure of the (111) facets and high content of oxygen vacancies showed an excellent OER performance with an overpotential of 307 mV at 10 mA cm⁻² and a Tafel slope as low as 55 mV dec⁻¹ and significantly superior to its counterpart with low content of oxygen vacancies or a broken Co₃O₄ dodecahedron being ground and losing the preferred facets of (111). The excellent OER performance should be attributed to the unique hollow structure and the effective control of the (111) facets and oxygen vacancies, which allows for more highly active sites and enhanced conductivity.

中文翻译：

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中空的Co3O4十二面体具有受控的晶体取向和氧空位，可用于高性能的析氧反应

对于氧释放反应（OER）的高级电催化剂的合理设计和制备是非常需要的，其中已采用各种策略来增强电催化活性，例如开发纳米结构，刻面控制和产生氧空位。本文中，我们已成功地将多种策略整合到一个催化系统中，以进一步提高OER性能。以ZIF-67为前驱体并在煅烧过程中调节气氛，制备了一系列具有受控晶体取向和氧空位的中空Co ₃ O ₄十二面体。中空Co ₃ O ₄具有（111）晶面受控暴露和高氧空位的十二面体显示出优异的OER性能，在10 mA cm ^-2时的超电势为307 mV，Tafel斜率低至55 mV dec ^-1，明显优于其氧空位含量低或Co ₃ O ₄十二面体破碎的对应物被磨碎，失去了（111）的优选刻面。优异的OER性能应归因于独特的中空结构以及对（111）晶面和氧空位的有效控制，从而可以实现更高的活性位点和更高的电导率。