Bacterial-cellulose-derived carbon nanofiber-supported CoFe2O4 as efficient electrocatalyst for oxygen reduction and evolution reactions

Exploration of cost-effective electrocatalysts with high catalytic activity toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remains a key challenge in the development of metal-air batteries. In this study, bacterial-cellulose-derived carbon nanofiber-supported CoFe2O4 (CFO/CNF) has been prepared via a facile and green method. The three dimensional (3D) interconnected CNF network support with high surface area not only provides high electronic conductivity but also promotes the mass transfer of O-2 and electrolyte during the ORR and OER. Furthermore, the strong coupling between CFO and CNF allows for fast charge transfer, facilitating the electrocataltyic processes. These lead to the high electrocatalytic activity of as-prepared CFO/CNF nanocomposite toward both the ORR and OER, outperforming CFO and CNF, respectively. Meanwhile, the stability of CFO/CNF nanocomposite toward the ORR and OER is much higher than that of benchmark Pt/C (20 wt.%) and RuO2/C (20 wt.%), respectively. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.