Synergistic effect of the one-pot formation of MnO2-Fe-Nx/carbon nanocomposites on the bifunctional catalytic activity for the oxygen reduction and evolution reactions

Abstract

Rational design of bifunctional electrocatalysts is crucial for developing efficient and cost-effective materials for energy conversion and storage systems. In this study, we designed an organic-inorganic nanocomposite material by incorporating MnO₂, which primarily exhibits catalytic activity in the oxygen evolution reaction (OER), and Fe-Nₓ-incorporated carbon nanoparticles, which show excellent performance in the oxygen reduction reaction (ORR). This MnO₂–Fe-Nₓ/C (MO-FN/CP) nanocomposite was obtained via a one-pot approach involving the plasma discharge in an organic–inorganic mixed precursor. The synergistic effect imparted by the individual components in the resulting MO-FN/CP nanocomposite system resulted in a higher catalytic activity for both ORR and OER. Notably, the bifunctional MO-FN/CP system exhibited a narrow potential gap of 0.75 V between the ORR and OER, which represents a more favorable bifunctional characteristic compared to commercial catalysts (Pt/C and RuO₂). These findings propose a new approach for constructing composite systems as bifunctional catalysts for electrochemical energy applications.