N-doped graphene wrapped hexagonal metallic cobalt hierarchical nanosheet as a highly efficient water oxidation electrocatalyst

Abstract

An N-doped graphene wrapped metallic Co nanosheet-on-nanosheet structure with a thickness of sub-4 nm and a high percentage of hexagonal Co phase as an efficient water oxidation electrocatalyst is presented. This sample exhibits an onset overpotential of 290 mV and performs comparably to RuO₂ at high current density due to the unique hexagonal Co and the wrapped N-doped graphene.