Exploring electrochemical and magnetic properties of Fe(III) coordination cluster: An efficient electrocatalyst for water oxidation

Abstract

In the present study, we investigated the electrochemical, water oxidation and magnetic properties of iron complex, [Fe6III(µ3-O)2(piv)6(edteH)2(N3)2] (1), (where = piv: pivalic acid and edteH4; N,N,N′,N′-Tetrakis(2-hydroxyethyl)ethylenediamine). To investigate the electrocatalytic activity of 1 for water splitting, linear sweep voltammetry (LSV) was executed to acquire the polarization curve at a scan rate of 5 mVs−1. Electrochemical Impedance Spectroscopy (EIS) was measured to obtain resistance values. The electrochemical investigation indicates about the high efficiency of the complex for the oxidation of water and overpotential 210 mV with 10 mA.cm−2 inclusive of Tafel slope of 88 m.V.dec−1. The high value of current density confirms about the proof of oxygen evolution behavior for the complex. In EIS study, the low value of charge transfer resistance indicates the fast kinetics in water-splitting process (OER) which complies with the LSV results and tafel slopes. In chronopotentiometry test, there was no significant catalytic degradation and no observable change in potential over 24 h that is confirmation about excellent stability of the compound. Magnetic study reveals the existence of strong antiferromagnetic interactions in this complex. Moreover, magnetization indicates a value of 10.02 at 70 kOe which is a good Brillouin fitting with S = 5.0 and g = 2.0.