Defective graphene for electrocatalytic CO reduction.

The rational synthesis of earth-abundant materials with excellent electrocatalytic performances plays a critical role in electrochemical CO reduction (ECR) to obtain value-added chemical products or fuels. Here we demonstrate a defective graphene (DG) as such an electrocatalyst candidate via a nitrogen removal method. The graphene with a large amount of topological defects offered abundant catalytically active sites, high electronic conductivity and strong adsorption of CO. Attributed to these features, the DG exhibited significantly higher electrocatalytic CO reduction performances with an excellent faradaic efficiency of ∼84% at -0.6 V vs. reversible hydrogen electrode and a larger current density, compared to pristine graphene, nitrogen-doped graphene and edge-rich graphene. This work suggests a promising method for further designing efficient metal-free electrocatalysts for CO reduction.