Polypyrrole assisted synthesis of nanosized iridium oxide for oxygen evolution reaction in acidic medium

Abstract

The application of electrochemical water splitting process in acidic medium is restricted by the lack of highly efficient and stable oxygen evolution reaction (OER) electrocatalyst. In this work, we report a facile soft template method to synthesize nanosized iridium oxide for electrocatalytic OER in acidic medium. The fabrication process involves thermal treatment of iridium complex and polypyrrole in air. The compositions and structures of the resulting catalytic materials are significantly influenced by the annealing temperature. The nanostructured iridium oxide synthesized at optimal 450 °C exhibits low overpotential (291.3 ± 6 mV) to reach 10 mA/cm2 current density towards OER, which is better than the commercial iridium oxide. Further investigation indicates that nanosized iridium oxide synthesized at 450 °C has high electrochemical active surface area to expose abundant accessible active sites, which can accelerate the OER rate. This method can also provide new guidance to prepare other metal oxide nanoparticles for various applications.