Silva Ana Luisa, Esteves Laura M, Silva Ludmila P C, Ramos Vitor S, Passos Fabio B, Carvalho Nakédia M F
Universidade do Estado do Rio de Janeiro, Departamento de Química Geral e Inorgânica Rio de Janeiro RJ 20550-900 Brazil
Universidade Federal Fluminense, Departamento de Engenharia Química e de Petróleo Niterói RJ 24210-240 Brazil
RSC Adv. 2022 Sep 21;12(41):26846-26858. doi: 10.1039/d2ra04570b. eCollection 2022 Sep 16.
This work reports the application of Mn-doped CoO oxides in the electrocatalytic oxygen evolution reaction (OER). The materials were characterized by structural, morphological, and electrochemical techniques. The oxides with higher Co : Mn molar ratio presented a lower electron transfer resistance, and consequently the most promising OER activities. Pure CoO shows an overpotential at = 10 mA cm of 761, 490, and 240 mV, at pH 1, 7, and 14, respectively, and a high TOF of 1.01 × 10 s at pH 14. Tafel slopes around 120 mV dec at acidic pH and around 60 mV dec at alkaline pH indicate different OER mechanisms. High stability for CoO was achieved for up to 15 h in all pHs, and no change in the structure and morphology after the electrocatalysis was observed. The reported excellent OER activity of the Mn-Co oxides in a wide pH range is important to broaden the practical applicability in different electrolyte solutions.
这项工作报道了锰掺杂氧化钴在电催化析氧反应（OER）中的应用。通过结构、形态和电化学技术对材料进行了表征。具有较高钴锰摩尔比的氧化物呈现出较低的电子转移电阻，因此具有最具前景的析氧反应活性。纯氧化钴在pH值为1、7和14时，电流密度为10 mA cm时的过电位分别为761、490和240 mV，在pH值为14时具有1.01×10 s的高周转频率。在酸性pH值下约120 mV dec和碱性pH值下约60 mV dec的塔菲尔斜率表明不同的析氧反应机制。在所有pH值下，氧化钴在长达15小时内都具有高稳定性，并且在电催化后未观察到结构和形态的变化。所报道的锰钴氧化物在宽pH范围内优异的析氧反应活性对于拓宽在不同电解质溶液中的实际应用具有重要意义。
