Nitrogen-doped 3D porous graphene coupled with densely distributed CoOx nanoparticles for efficient multifunctional electrocatalysis and Zn-Air battery

Abstract

Highly efficient and low-cost multifunctional electrocatalysts play a crucial role in energy storage and conversion systems. Herein, a new strategy is developed based on a structured precursor to design and fabricate a hierarchical porous nitrogen doped graphene coupled with densely distributed CoO/Co3O4 heterostructure that exhibits outstanding multifunctional activities. With rational hybridization of graphene and bimetallic nanoparticles, the as-obtained NGPC@CoOx integrated densely distributed CoO/Co3O4 active nanoparticles to 3D interconnected hierarchical N-doped graphene mesh, which gives rise to a multifaceted capability for electron/ion transfer and redox catalyzing. The NGPC@CoOx possesses excellent durability with a superior E1/2 of 0.86 V for oxygen reduction reaction (ORR), and a relatively low potential for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of 1.61 V, and -0.162 V at 10 mA cm−2, respectively. Additionally, the superior cycling durability and high power density of NGPC@CoOx-based zinc-air batteries (184.4 mW cm−2) further confirm the potential application of prototype devices. This work introduces a new perspective on developing efficient multifunctional electrocatalysts with a well-designed 3D structure anchored with densely distributed nanoparticles towards energy storage and conversion technologies.