A high entropy spinel oxide (Cr_0.2Mn_0.2Fe_0.2Ni_0.2Zn_0.2)₃O₄ is successfully synthesized via the solvothermal method, and its electrocatalytic properties for the oxygen evolution reaction (OER) are evaluated. The catalyst exhibits a low overpotential of 295 mV at 10 mA cm⁻², with a Tafel slope of 53.7 mV dec⁻¹ as well as promising long-term stability. The attractive performance can be attributed to the increased amount of high valence Ni³⁺ species, together with the improved adsorption ability of oxygenic species on the material surface, due to the contribution of the multi-metallic element doping strategy in high entropy spinel oxide. DFT calculation results prove that the covalency of the metal–oxygen bond is enhanced in the high entropy oxide, which is beneficial for the OER catalysis. The DOS profile analysis and different charge density mapping results further reveal the multi-metal synergistic contribution to the oxygen evolution reaction. This study provides a reference method for the design and development of high-entropy spinel oxides with excellent OER properties.

中文翻译：

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高熵尖晶石 (Cr0.2Mn0.2Fe0.2Ni0.2Zn0.2)3O4 用于析氧反应的电催化活性和稳定性共荣

采用溶剂热法成功合成了高熵尖晶石氧化物(Cr _0.2 Mn _0.2 Fe _0.2 Ni _0.2 Zn _0.2 ) ₃ O ₄，并评价了其对析氧反应(OER)的电催化性能。^{该催化剂在 10 mA cm -2}下表现出 295 mV 的低过电位，具有 53.7 mV dec ^-1的 Tafel 斜率以及有希望的长期稳定性。有吸引力的性能可以归因于高价Ni ^{3+的量增加}由于多金属元素掺杂策略在高熵尖晶石氧化物中的贡献，物质以及含氧物质在材料表面的吸附能力得到了提高。DFT计算结果证明金属-氧键的共价键在高熵氧化物中增强，有利于OER催化。DOS曲线分析和不同的电荷密度映射结果进一步揭示了多金属对析氧反应的协同作用。该研究为设计和开发具有优异OER性能的高熵尖晶石氧化物提供了参考方法。