A two-dimensional manganese-containing coordination polymer for efficient catalysis of the oxygen evolution

Abstract

The structural stability of coordination polymers is very important to act as efficient catalysts. A novel two dimensional manganese based coordination polymer [Mn2(ox)(sqr)(dmso)2]n (Mn-CP) {ox = oxalate, sqr = squarate, dmso = dimethylsulfoxide} has been fabricated, keeping in consideration that the extensive delocalization of π-electron densities of both non-innocent redox active ligands will make a manganese an efficient oxygen-evolving centre by improving its poor intrinsic conductive nature. Mn-CP has displayed excellent OER performance at neutral pH, exhibiting a current density (J) of 10 mA/cm2 at an overpotential (η) of 300 mV (vs. RHE), with a Tafel slope (TS) of 82.4 mV/dec in PBS (pH = 7.4). The enhanced water oxidizing ability can be credited to the unique two-dimensional planer-conducting layers of oxalates and squarates with Mn2+ ions. FT-IR, PXRD and controlled potential electrolysis (CPE) investigate that Mn-CP stays functional and structurally intact for a period of 10 hours.