Galvanic replacement mediated synthesis of rGO-Mn₃O₄-Pt nanocomposites for the oxygen reduction reaction

Pt-based nanomaterials are considered to be the most efficient electrocatalysts in various energy devices. Here we demonstrate a galvanic replacement mediated synthesis of hybrid rGO-Mn₃O₄-Pt nanocomposites as efficient electrocatalysts for the oxygen reduction reaction (ORR) in alkaline solutions. rGO-Mn₃O₄-Pt nanocomposites were obtained through galvanic replacement between Mn₃O₄ and Pt⁴⁺ ions, where the 8-10 nm Mn₃O₄ was homogeneously fabricated on the rGO surface. It was found that the distribution of Pt nanoparticles could be effectively modulated by the amount of Pt⁴⁺ ions. The as-prepared rGO-Mn₃O₄-Pt-1, with 2-3 nm Pt nanoparticles uniformly dispersed on the rGO-Mn₃O₄ support and 10 wt% Pt loading, even displays superior ORR catalytic activity to the commercial 20% Pt/C material. We believe the as-prepared rGO-Mn₃O₄-Pt nanocomposites are appealing for energy devices due to their excellent electrocatalytic performance and the decreased use of precious Pt.