LAUSR

Abstract Three Co(II)-MOFs, catena- [(diaqua-(μ2-bqdc-κO,O)-(phen-κN,N)-cobalt (II)] (1), { [Co(pa)(4,4′-bipy)(H2O) (CH3OH)]•DMF}n (2) and [Co(ia)(bpe)0.5(H2O)]n (3), (H2bqdc=2,2-biquinoline-4,4′-dicarboxylic acid, phen = 1,10-phenanthroline), (H2pa = pamoic acid) (H2ia = itaconic acid, bpe = 1,2-bi(4-pyridyl)ethane) have been re-synthesized and thoroughly characterized by FT-IR, PXRD, SEM, EDX, HRTEM, BET surface area and UV/vis techniques. The objective of choosing three Co(II)-MOFs 1-3 composed of different ligands and having 1D, 2D and 3D structures, respectively, was to have deep insights into role of linked ligands and the structural morphology toward electrocatalytic performance. MOFs 1-3 have been examined as electrocatalysts for water oxidation and comparative assessments revealed their catalytic performance in the order 2 > 3 ≈ 1. MOF 2 shows the best electrocatalytic activity for OER, which could be due to the higher amount of cobalt present in MOF-2, faster electron transfer kinetics and higher effective electrode surface area. The onset potential of MOF 2 was comparable or less as compared to benchmark catalysts IrO2 and Pt/C. Overall studies strongly suggest that MOF 2 could be promising materials for replacement of commercial high-cost electrode material.