In-situ synthesis strategy for CoM (M = Fe, Ni, Cu) bimetallic nanoparticles decorated N-doped 1D carbon nanotubes/3D porous carbon for electrocatalytic oxygen evolution reaction

The exploration of earth-abundant non-precious metals electrocatalysts for oxygen evolution reaction (OER) is one of the key issues for water splitting. Metal-organic frameworks (MOFs) possessing the metal ions centers and organic ligands are one of promising precursors for fabricating metal-containing carbon based OER electrocatalysts via a simple carbonization process. Here, a series of MOFs derived CoM (M = Fe, Ni, Cu) bimetallic nanoparticles decorated N-doped 1D carbon nanotubes/3D porous carbon have been synthesized as high performance and robust electrocatalysts for OER. All of the binary metal doped electrocatalysts not only show smaller overpotential for OER at a current density of 10 mA cm−2 and a lower Tafel slope, but also exhibit a remarkable long-term durability in alkaline aqueous solution. It is discovered that in-situ incorporation of Fe, Ni, Cu into MOFs derived carbon materials can modulate the electronic structure of the electrocatalysts, forming more catalytically active sites, increasing electrochemically-active areas (ECSA) and facilitating electron mass transport and electron transfer during the OER process. Moreover, the 3D porous structure can also promote the exposure of active sites, provide a larger surface area for electrocatalysts to contact the electrolyte and construct a favorable catalytic interface, thus advancing the electrocatalytic performance. This work develops a general approach to preparing the efficient and robust carbon based electrocatalyts derived from MOFs precursors.