How to switch from a poor PEDOT:X oxygen evolution reaction (OER) to a good one. A study on dual redox reversible PEDOT:metallacarborane

Abstract

Over the years, extensive research has been carried out to optimize the oxygen evolution reaction (OER) by adopting different techniques as well as catalysts. Conducting organic polymers such as PEDOT have been employed to study the reaction but have failed to lower the over-potential for the reaction. Here we show electrochemically made, intimately blended, dual redox reversible materials incorporating PEDOT and metallacarboranes. The metallacarboranes act as doping agents but with tunable E_1/2 potentials. The tunability of E_1/2 allows the overlapping of the two redox potentials which subsequently leads to their synergy. The physico-chemical properties of the metallacarboranes fade and become integrated with PEDOT to form a dual redox reversible system. Therefore, the properties of the dopant are modified by the polymer. Thus, due to its high E_1/2, the Co^4+/3+ couple would not be an efficient electrocatalyst for water oxidation but when it is immersed in the PEDOT matrix the Co^4+/3+ potential is more accessible so that very low overpotential values are obtained, which justifies the title of the work, How to switch from a poor PEDOT:X oxygen evolution reaction (OER) to a good one. The dual redox reversible system has been extensively characterized and has been shown to be a promising candidate for the water oxidation reaction.