Porous Hollow-Structured LaNiO₃ Stabilized N,S-Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

A nanohybrid based on porous and hollow interior structured LaNiO₃ stabilized nitrogen and sulfur codoped graphene (LaNiO₃/N,S-Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O₂-saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow-structured LaNiO₃ spheres and heteroatom doped efficiency on graphene structure. In addition, N,S-Gr can meritoriously stabilize monodispersion of the LaNiO₃ spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O₂ adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non-Pt catalysts for ORR in alkaline media.