Abstract Co3O4 with different morphologies including nanomeshs, nanorods, and nanowires structures were prepared by one-step hydrothermal method using various precursors. The Co3O4 nanowires arrays showed the optimal oxygen evolution reaction (OER) performance with an overpotential of 394 mV at 20 mA cm−2 and Tafel slope of 112 mV dec−1 in alkaline electrolyte. Subsequently, the effect of Ni doping on OER activity of Co3O4 nanowires arrays was further studied under identical conditions. Notably, the as-prepared 12% Ni-Co3O4 (the molar ratio of Ni to Co is 12%) rendered the best activity with a low overpotential of 340 mV to achieve 20 mA cm−2 and Tafel slope of 60 mV dec−1, and superior stability, outperforming other Ni-Co3O4 samples. Density functional theory (DFT) calculations revealed that the theoretical overpotentials of Co3O4 and Ni-Co3O4 were calculated to be 1.70 V and 0.51 V, respectively, and the chemical conversion from OH* to O* is the rate-limiting step (RLS) with energy barrier of 1.74 eV for Ni-Co3O4. Therefore, this study provides a promising method for designing highly active and stable substitution for noble metal catalysts toward OER.

中文翻译：

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含镍的 Co3O4 形态控制用于高效析氧反应

摘要 使用各种前驱体，通过一步水热法制备了具有不同形貌的Co3O4，包括纳米网、纳米棒和纳米线结构。Co3O4 纳米线阵列显示出最佳的析氧反应 (OER) 性能，在碱性电解质中，20 mA cm-2 下的过电位为 394 mV，塔菲尔斜率为 112 mV dec-1。随后，在相同条件下进一步研究了 Ni 掺杂对 Co3O4 纳米线阵列 OER 活性的影响。值得注意的是，所制备的 12% Ni-Co3O4（Ni 与 Co 的摩尔比为 12%）呈现最佳活性，低过电位为 340 mV，可实现 20 mA cm-2 和 60 mV dec-1 的 Tafel 斜率和卓越的稳定性，优于其他 Ni-Co3O4 样品。密度泛函理论 (DFT) 计算表明，计算出的 Co3O4 和 Ni-Co3O4 的理论过电位分别为 1.70 V 和 0.51 V，并且从 OH* 到 O* 的化学转化是限速步骤 (RLS) Ni-Co3O4 的能垒为 1.74 eV。因此，这项研究为设计高活性和稳定的贵金属催化剂替代 OER 提供了一种有前景的方法。