Co@N-doped carbon nanomaterial derived by simple pyrolysis of mixed-ligand MOF as an active and stable oxygen evolution electrocatalyst

Abstract

Design and synthesis of cost effective, non-noble and efficient electrocatalysts for oxygen evolution reaction (OER) has prospective in the development of various renewable energy storage and conversion devices. We developed metallic cobalt encased N-doped carbon hybrid nanomaterial with remarkable electrochemical activity from a three-dimensional cobalt (II) based N-containing MOF as a sacrificial template by carbonization. All the carbonized materials have been characterized by various analytical methods to establish the structural and morphological integrity. N-doped graphitic carbon embedded with metallic cobalt (CoNC-900) revealed promising electrochemical activity towards OER in alkaline and hydrogen evolution in acidic media with good stability. Among the series of carbonized MOF material CoNC-900 is designated as highly efficient electrode materials with low overpotential/Tafel slope and superior stability for OER. Standard current density of 10 mA cm−2 was attained at a smaller overpotential (210 mV) by CoNC-900 compared to state-of-the-art RuO2 electrocatalyst (280 mV) indicating OER kinetics response is significantly higher showing the superior activity outperforming most reported electrocatalysts. In view of the best OER performance, experiments have been performed to gauge the electrochemically active surface area, stability/durability and charge transfer resistance (Rct), which also supports the efficient electrocatalytic performance observed in CoNC-900.