Electrocatalytic reduction of oxygen by metal coordination polymers produced from pentacyanidoferrate(II) complex

Pentacyanidoferrates can be used as building blocks to produce coordination polymers to be applied in electrocatalysis. The electrochemical properties of these materials can be modulated according to the nature of the ligands in the precursor complexes. Herein, we report the preparation of a new electroactive coordination polymer prepared by the reaction between Fe3+ and [Fe(CN)(5)(ptt)](3) (ptt = 5-(4-pyridyl)1H-1,2,4-triazole-3-thiol). The produced material was used as electrocatalyst in experiments of reduction of molecular oxygen. For this reason, fluorine doped tin oxide (FTO) glass substrates were modified with gold nanoparticles and the electroactive coordination polymers produced. The experiments revealed an increase 64% in the reduction current of oxygen and a decrease 80 mV in the onset potential of oxygen reduction when compared to the bare FTO electrode. Thus, we suggest a synergic effect between the high surface area of the gold nanoparticles and the electrochemical activity of the coordination polymer produced. (C) 2017 Elsevier B.V. All rights reserved.