Morphology control of Co3O4 with nickel incorporation for highly efficient oxygen evolution reaction
Morphology control of Co3O4 with nickel incorporation for highly efficient oxygen evolution reaction
复制标题
DOI：
10.1016/j.apsusc.2020.148221
复制
发表时间：
2021-03
影响因子：
6.7
通讯作者：
Haozhe Du;Wen-hong Pu;Changzhu Yang
中科院分区：
文献类型：
--
作者：
Haozhe Du;Wen-hong Pu;Changzhu Yang
采用一步水热法制备了不同形貌的Co 3 O 4，包括纳米网、纳米棒和纳米线结构。Co 3 O 4纳米线阵列显示出最佳的析氧反应（OER）性能，在碱性电解液中，20 mA cm-2时的过电位为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Co 3 O 4纳米线阵列OER活性的影响。值得注意的是，所制备的12% Ni-Co 3 O 4（Ni与Co的摩尔比为12%）呈现最佳活性，具有340 mV的低过电位，以实现20 mA cm-2和60 mV dec-1的Tafel斜率，以及优越的上级稳定性，优于其他Ni-Co 3 O 4样品。密度泛函理论（DFT）计算表明，Co 3 O 4和Ni-Co 3 O 4的理论过电位分别为1.70 V和0.51 V，Ni-Co 3 O 4的OH ~* 向O ~* 的化学转化是反应的限速步骤，其能垒为1.74 eV.因此，本研究为设计高活性、高稳定性的贵金属替代催化剂提供了一种新的方法。
Co3O4with different morphologies including nanomeshs, nanorods, and nanowires structures were prepared by one-step hydrothermal method using various precursors. The Co3O4nanowires arrays showed the optimal oxygen evolution reaction (OER) performance with an overpotential of 394 mV at 20 mA cm−2and Tafel slope of 112 mV dec−1in alkaline electrolyte. Subsequently, the effect of Ni doping on OER activity of Co3O4nanowires 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−2and Tafel slope of 60 mV dec−1, and superior stability, outperforming other Ni-Co3O4samples. Density functional theory (DFT) calculations revealed that the theoretical overpotentials of Co3O4and Ni-Co3O4were 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.