Construction of highly-stable graphene hollow nanospheres and their application in supporting Pt as effective catalysts for oxygen reduction reaction

The construction and surface modification of three-dimensional (3D) graphene structures have been recognized as effective ways to prepare high-performance graphene-based composites in energy-related applications. Herein, on the basis of well-defined morphology and efficient electron conduction, the 3D highly-stable graphene hollow nanospheres have been synthesized by using sacrificial template method. The as-prepared 3D graphene nanospheres exhibit superior mechanical stability, electrochemical stability, and strong hydrophobicity, which may accelerate the emission of H2O in acidic medium-based ORR. Accordingly, the 3D highly-stable graphene nanospheres are used to confine tiny Pt nanoparticles (3D r-GO@Pt HNSs) for ORR in acidic medium, exhibiting superior activity with 4-electron-transfered pathway. Meanwhile, dramatically improved durability are achieved in terms of both ORR mass activity and electrochemically surface area compared to those of commercial Pt/C. We report a sacrificial template-based stratagem to prepare 3D highly-stable graphene hollow nanospheres supported Pt nanohybrids (3D r-GO@Pt HNSs). Benefiting from the unique structural and compositional advantages, the 3D r-GO@Pt HNSs exhibit observably enhanced ORR activity and excellent stability under acidic condition. [Display omitted]