Abstract

Graphical Abstract To replace precious platinum (Pt)-based electrocatalysts for cathodic oxygen reduction reaction (ORR), edge-selectively sulfurized graphene nanoplatelets (SGnP) are synthesized as efficient metal-free electrocatalysts simply by ball-milling pristine graphite in the presence of sulfur (S8). The resultant SGnPs exhibit remarkable electrocatalytic activity toward ORR with better tolerance to methanol crossover/CO poisoning effects and longer-term stability than those of pristine graphite and commercial Pt/C electrocatalysts. Edge-Selectively Sulfurized Graphene Nanoplatelets as Efficient Metal-Free Electrocatalysts for Oxygen Reduction Reaction: The Electron Spin Effect