Polyaniline coating enables electronic structure engineering in Fe3O4 to promote alkaline oxygen evolution reaction

The electronic structure of active sites is of importance for catalysts to achieve an optimized interaction with the intermediates. In this study, a unique organic-inorganic hybrid oxygen evolution reaction electrocatalyst composed of electrochemically inactive conducting polyaniline (PANI) and non-precious Fe-based oxide Fe3O4is presented. PANI molecules werein situloaded on Fe3O4nanoparticles through an efficient and simple process under mild conditions. The electronic structure of Fe3O4was modulated by creating a strong interaction with PANI molecules, leading to enhanced activity and stability of the catalyst to achieve 10 mA cm-2geometrical current density at overpotential of 265 mV in 1 M aqueous KOH solution. This work demonstrates that a highly efficient electrocatalyst can be achieved by molecular modification and provides a novel strategy for the optimization of the inactive non-precious catalysts.