Enhancing the electrocatalytic activity via hybridization of Cu(I/II) oxides with Co3O4 towards oxygen electrode reactions

• Published in: Journal of power sources Vol. 490; p. 229511
• Main Authors: Hazarika, Kumar Kashyap, Yamada, Yusuke, Matus, Ekaterina V., Kerzhentsev, Mikhail, Bharali, Pankaj
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2021
• Subjects: Electrocatalysis; Mixed valence oxides; Oxygen evolution reaction; Oxygen reduction reaction; Electrocatalysis; Oxygen evolution reaction; Oxygen reduction reaction; Mixed valence oxides
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2021.229511

Transition metal oxide based electrocatalysts (ECs) with mixed valence state have gained considerable attention in recent times. Herein, Co3O4–CuO/Cu2O/C nanostructure with mixed valence oxides is reported as an efficient bi-functional EC towards oxygen electrode reactions in alkaline medium. The EC displays higher current density of 6.2 mA cm−2 and mass activity of 12.9 mA mg−1 compared to that of commercially available Pt/C in 0.1 M KOH solution for oxygen reduction reaction (ORR). Rotating disk electrode measurements are used to understand the kinetics of the reaction and the EC is durable up to 1000 redox cycles. The material is highly stable up to 7000 s by retaining 99% of its initial current. The fast electron transfer is established by the smaller Tafel slope value of 83.6 mV dec−1. In addition, the prepared material is also active for oxygen evolution reaction (OER) in 0.1 M KOH solution. Thus, the nanostructure with different bimetallic active sites is found to be a potential material for oxygen electrocatalysis. •A Co3O4–CuO/Cu2O material is employed as electrocatalyst for ORR/OER in alkaline medium.•The ORR follows a direct four electron pathway.•Performance of the material is much higher than the Pt/C under similar conditions.•The material is also active for OER.•The material is highly durable and stable.