Multifunctional graphene-based nanostructures for efficient electrocatalytic reduction of oxygen

Graphene derivatives have been used extensively as a functional support for nanoparticle catalysts in diverse applications, in particular, oxygen reduction reactions (ORR) at fuel cell cathodes. This review summarizes recent progress in this area of research, where the catalytic performance is evaluated within the context of stabilization of metal nanoparticles against sintering/aggregation and metal–substrate interactions that manipulate the electronic properties of metal nanoparticles and hence the bonding interactions with reaction intermediates. Also discussed are the latest breakthroughs of heteroatom-doped graphene derivatives as effective metal-free catalysts for oxygen reduction. In addition, the review includes a perspective on the development of effective ORR catalysts with a focus on a further understanding of the ORR mechanism as well as on other two-dimensional layered nanostructures such as MoS2 that have been observed to exhibit electrocatalytic activity for oxygen reduction. Leadingmechanistic models are discussed to account for the electrocatalytic activity. © 2015 Society of Chemical Industry