metal-organic framework derived co3o4 as a an efficient bifunctional electrocatalyst for the overall water splitting reaction

Abstract: with the gradual depletion of conventional energy resources, including petroleum and natural gas, exploring renewable energy sources has become the spotlight of attention over the past few decades [1]. among the renewable energy sources, molecular hydrogen is a promising candidate due to its high heat value and zero-carbon emission [1]. electrolysis of water has been considered a sustainable and environmentally friendly technique for the green production of hydrogen fuel [1]. however, it is hindered by the sluggish kinetics and high overpotentials of the corresponding half-reactions, namely, the hydrogen evolution reaction (her) and the oxygen evolution reaction (oer). therefore, developing low-cost and high-efficiency electrocatalysts to boost water splitting performance is a priority. in recent years, low-cost co-based materials have been extensively investigated as alternatives to the conventional noble metal-based catalysts for electrochemical water splitting [2]. metal-organic frameworks (mofs), a comprehensive novel class of crystalline and nanoporous materials, are constructed utilizing metal ions and multifunctional organic ligands.mofs have been widely used as ideal templates or precursors to make metal oxides with various morphologies [3]. in the present study, we report a facile and convenient method to synthesize mof-derived co3o4 as an efficient electrocatalyst for the overall water splitting reaction. the electrocatalytic performance of co3o4 on ni foam (co3o4/nf) was far superior to the co-mof/nf. co3o4/nf exhibited low overpotentials of 300 and 335 mv to deliver the current density of 50 ma/cm2 in oer and her, respectively, along with excellent long-term electrochemical stability. moreover, it displayed small tafel slopes of 77 and 67 mv/decade in oer and her, respectively, indicating the fast reaction kinetics. in summary, this work provides new insights for designing efficient mof-based bifunctional electrocatalysts for the overall water splitting reaction.