Abstract

In this work, different cobalt-based mixed transition metal oxides (MTMOs) were fabricated by hydrothermal process followed by calcination. Doping Co₃O₄ with other transition metals, such as Ni, Cu, and Mn, resulted in a fascinating morphological transformation from quasi-spherical nanoparticles to hierarchical micro/nanostructures. Hollow urchin-like NiCo₂O₄ exhibited a high specific surface area which led to excellent electrochemical performance towards oxygen evolution reaction (OER). It achieved a low overpotential of about 309 mV at 10 mA/cm² current density, which is comparable to other reported electrocatalysts. Cyclic voltammetry (CV) technique revealed the redox processes that occur on the surface of NiCo₂O₄ and supported that Co⁴⁺ could be the active center during electrocatalysis. In general, the excellent electrocatalytic activity, stability, and reversibility of NiCo₂O₄ in alkaline condition suggest its applicability as an OER electrocatalyst.

中文翻译：

---

碱性介质中分层/纳米结构混合过渡氧化钴的电催化氧析出反应

摘要

在这项工作中，通过水热工艺然后煅烧制备了不同的钴基混合过渡金属氧化物（MTMO）。用其他过渡金属（例如Ni，Cu和Mn）掺杂Co ₃ O ₄导致了从准球形纳米粒子到分层微观/纳米结构的迷人形态转变。中空的类似顽童的NiCo ₂ O ₄表现出高的比表面积，这导致其对氧放出反应（OER）的出色电化学性能。它在10 mA / cm ^2时实现了约309 mV的低过电势电流密度，可与其他已报道的电催化剂相媲美。循环伏安法（CV）技术揭示了NiCo ₂ O ₄表面发生的氧化还原过程，并证明Co ⁴⁺可能是电催化过程中的活性中心。通常，NiCo ₂ O ₄在碱性条件下优异的电催化活性，稳定性和可逆性表明其可作为OER电催化剂应用。