Synthesis of a Hierarchically Porous C/Co 3 O 4 Nanostructure with Boron Doping for Oxygen Evolution Reaction

Abstract Fabricating a low‐cost and highly efficient electrocatalyst is of importance for the development of renewable energy devices. In this work, we have synthesized an ultrafine cobalt oxide nanocatalyst (5–10 nm) doped with boron (BC/Co 3 O 4 ) by using a metal–organic framework as a precursor, which exhibits an excellent catalytic activity for oxygen evolution reaction (OER). Owing to the improvement of accessible active sites by boron doping, the synthesized catalyst can reach a current density of 10 mA cm −2 at 1.54 V with a low overpotential of 310 mV, superior than those of commercial RuO 2 and N‐doped C/Co 3 O 4 . This work provides a facile way to develop highly efficient catalysts for electrochemical reactions.