A sandwich N-doped graphene/Co3O4 hybrid: an efficient catalyst for selective oxidation of olefins and alcohols

Abstract

A sandwich-like N-doped graphene/Co₃O₄ hybrid was prepared via a simple one-pot hydrothermal reaction in a solution of NH₃. Characterizations disclosed that highly dispersed Co₃O₄ nanoparticles with dominant exposed {112} and {110} planes were fabricated on both sides of well-exfoliated N-doped graphene; N-dopants in the graphene matrix can prevent re-graphitization of graphene, strengthen the interaction between Co₃O₄ and the graphene matrix, and improve the dispersion of Co₃O₄. This hybrid (Co₃O₄/RGO-_N) exhibited superior activity and stability for the epoxidation of styrene compared to bulk Co₃O₄ and N-free graphene supported Co₃O₄. At the same time, the resulting catalyst also showed high compatibility with various olefins and alcohols with good conversion and high selectivity. This synergistic strategy can provide simple, efficient and versatile blue-prints for low-cost fabrication of graphene-based nanocomposites for extending applications where graphene has rarely been exploited and beyond.