The design of high-efficiency non-precious electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is extremely important for developing sustainable energy technologies. Herein, we report a metal–organic framework (MOF) template carbonization route to prepare a Co-based hybrid electrocatalyst with superior performance for both HER and OER in an alkaline solution. Starting from a carbon nanotube (CNT) inserted Co MOF, the Co-NC/CNT hybrid with a N-doped carbon nanoframe composed of hollow Co nanoparticles interlinked by CNTs is first synthesized via carbonization. This unique 3D structure is shown to have highly exposed active sites and good conductivity. Most importantly, the Co-NC/CNT hybrid can act as bifunctional catalysts on both anode and cathode for electrochemical water splitting, to deliver a current density of 10 mA cm⁻² under a cell voltage as low as 1.625 V.

        https://doi.org/10.1039/C6TA05829A