Ultrathin two-dimensional cobalt-organic framework nanosheets as an effective electrocatalyst for overall water splitting under alkaline conditions

Abstract

Recently, two–dimensional, 2D, metal–organic frameworks, MOFs, have developed as an irreplaceable category of multifunctional materials because of their excellent conductivity, large specific surface area, and porous structure. One of the most important factors in the electrocatalytic behavior of 2D MOFs is their exposure facet, which is determined by their preparation method. Here, we have prepared 2D ZIF-67 with exposure (211) facet and compared its electrocatalytic property toward water oxidation and hydrogen evolution to nanostructured ZIF-67 in alkaline solution. Our findings showed that the prepared 2D ZIF-67 has 27 and 151 mV overpotentials lower than ZIF-67 nanoparticles for water oxidation and hydrogen evolution reactions, respectively. Also, it offers the Tafel slopes as around one–half as those ZIF-67 nanoparticles for both water oxidation and hydrogen evolution reactions verifying a more facile kinetic for both reactions on the surface of 2D ZIF-67.