Facile construction of S-containing Co-based metal organic framework core–shell microspheres as an efficient bifunctional oxygen electrocatalyst

Abstract

A cost-effective non-noble metal bifunctional electrocatalyst towards the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is very important for energy-related applications. Micro/nanomaterials with core–shell structures have emerged as potential non-noble metal catalyst candidates. Herein, an efficient bifunctional oxygen electrocatalyst, S-containing Co-based metal organic framework core–shell microspheres (Co-MOF-CSMSs), has been designed and constructed by using 2,2′:5′,2′′-terthiophene-5,5′′-dicarboxylic acid as a novel ligand through a facile one-step hydrothermal method. Due to the integrated favorable structural characteristics of the core–shell structure and MOFs for electrocatalysis, Co-MOF-CSMSs are revealed as a good bifunctional electrocatalyst for the ORR and OER, including an onset potential of 0.93 V vs. RHE (reversible hydrogen electrode), a half-wave potential of 0.78 V vs. RHE and an overpotential of 0.35 V at 10 mA cm⁻². This work provides a low-cost and facile method to design and construct advanced micro/nanomaterials with core–shell structures to targetedly develop high-performance bifunctional oxygen electrocatalysts.