Developing cost-effective and high-performance oxygen evolution reaction (OER) electrocatalysts has become the intense research on pursuing emerging renewable energy conversion, in which exploring and investigating the intrinsic nature of efficient and stable CuCo spinel catalysts toward OER in alkaline media is highly desirable. Herein, Cu_1−xCo_2+xO₄ oxy-spinel nanoflakes are fabricated by a facile hydrothermal method with the oxidation of ammonia water. In the same condition, Cu_1−x-Co_2+xS₄ thio-spinel nanospheres are formed without oxidation. In OER process, the as-obtained Cu_1−xCo_2+xO₄ nanoflakes and Cu_1−xCo_2+xS₄ nanospheres possess the anodic overpotential of 267 and 297 mV in alkaline media to drive the current density of 10 mA/cm², respectively, outperforming the state-of-the-art noble metal catalyst of RuO₂. X-ray photoelectron spectroscopy analysis exhibits the higher ratio value of Co(III)/Co(II) in Cu_1−xCo_2+xO₄ than that in Cu_1−xCo_2+xS₄, suggesting that the strongly-electronegative oxygen efficiently predominates in regulating valence states of Co active sites in spinel structures. Remarkably, density functional theory simulation further reveals that the increased valence state of Co could accelerate the electron exchange between catalysts and oxygen adsorbates during electrocatalysis, thus contributing to the higher OER activity of Cu_1−xCo_2+xO₄ catalysts. This work provides deep insight regarding the significance of non-metal element (O and S) in CuCo spinel structure catalysts, as well as presents a promising approach to exploit higher performance and grasp the mechanism of various non-noble-metal spinel catalysts for water oxidation.

开发具有成本效益和高性能的氧气析出反应（OER）电催化剂已成为追求新兴可再生能源转化的重点研究，其中迫切需要探索和研究在碱性介质中高效稳定的CuCo尖晶石催化剂对OER的内在本质。 。在此，通过简便的水热法并利用氨水的氧化来制造Cu _{1- x} Co _{2+ x} O ₄氧-尖晶石型纳米薄片。在相同条件下，形成Cu _{1- x} -Co _{2+ x} S ₄硫代-尖晶石纳米球而没有氧化。在OER过程中，获得的Cu ₁ - _x Co_{2+ x} O ₄纳米薄片和Cu _{1- x} Co _{2+ x} S ₄纳米球在碱性介质中具有267和297 mV的阳极超电势，分别驱动10 mA / cm ²的电流密度，性能优于RuO ₂的最新贵金属催化剂。X射线光电子能谱分析显示，Cu _{1- x} Co _{2+ x} O _4中的Co（III）/ Co（II）比值比Cu _{1- x} Co _{2+ x} S _{4中的高。}，表明强负电氧有效地调节了尖晶石结构中Co活性位的价态。值得注意的是，密度泛函理论模拟进一步揭示了Co价态的增加可以加速电催化过程中催化剂与氧吸附物之间的电子交换，从而有助于提高Cu _{1- x} Co _{2+ x} O ₄催化剂的OER活性。这项工作为CuCo尖晶石结构催化剂中非金属元素（O和S）的重要性提供了深刻的见解，并提出了一种有前途的方法，以开发更高的性能并掌握各种非贵金属尖晶石催化剂用于水的机理。氧化。