Aluminium, Nitrogen‐Dual‐Doped Reduced Graphene Oxide Co‐Existing with Cobalt‐Encapsulated Graphitic Carbon Nanotube as an Activity Modulated Electrocatalyst for Oxygen Electrocatalyst for Oxygen Electrochemistry Applications

Abstract

AbstractThere is a rising need to create high‐performing, affordable electrocatalysts in the new field of oxygen electrochemistry. Here, a cost‐effective, activity‐modulated electrocatalyst with the capacity to trigger both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in an alkaline environment is presented. The catalyst (Al, Co/N‐rGCNT) is made up of aluminium, nitrogen‐dual‐doped reduced graphene oxide sheets co‐existing with cobalt‐encapsulated carbon nanotube units. Based on X‐ray Absorption Spectroscopy (XAS) studies, it is established that the superior reaction kinetics in Al, Co/N‐rGCNT over their bulk counterparts can be attributed to their electronic regulation. The Al, Co/N‐rGCNT performs as a versatile bifunctional electrocatalyst for zinc‐air battery (ZAB), delivering an open circuit potential ≈1.35 V and peak power density of 106.3 mW cm−2, which are comparable to the system based on Pt/C. The Al, Co/N‐rGCNT‐based system showed a specific capacity of 737 mAh gZn−1 compared to 696 mAh gZn−1 delivered by the system based on Pt/C. The DFT calculations indicate that the adsorption of Co in the presence of Al doping in NGr improves the electronic properties favoring ORR. Thus, the Al, Co/N‐rGCNT‐based rechargeable ZAB (RZAB) emerges as a highly viable and affordable option for the development of RZAB for practical applications.