In Situ Growth of Co3O4 Nanoparticles on Interconnected Nitrogen-Doped Graphene Nanoribbons as Efficient Oxygen Reduction Reaction Catalyst

A simple, low cost and nontoxic preparation method to obtain high performance oxygen reduction reaction (ORR) catalysts is of great significance in fuel cell fields. Herein, graphene nanoribbons (GNRs) with numerous graphitic edges are chosen as supporting material to hybridize with nitrogen atoms and cobalt oxide (Co3O4) through a simple one-step hydrothermal reaction. With a high edgeto-plane ratio, the GNR sheets could increase the accessibility of N-atom doping into the graphene edges to form active ORR sites, and be also interconnected with each other to form a conductive network, thus facilitating the fast electron transfer. The intimate contacts between Co3O4 nanoparticles and nitrogen-doped GNRs (N-GNRs) along with the porous structure impart the N-GNR/Co3O4 hybrid with excellent ORR performance, which leads to a comparable onset-potential to commercial Pt/C catalyst but larger current density, better long-term stability and superior tolerance to crossover effects.