Fabricating Sulfur/Oxygen Co-Doped Crumpled Graphene for High-Performance Oxygen Reduction Reaction Electrocatalysis

Herein, defect-rich graphene oxide with a crumpled form was fabricated through the fast thermal expansion of H 2 SO 4 -intercalated graphite oxide. The fast removal of intercalated H 2 SO 4 molecules and by-product gases result in the formation of crumpled edges, whereas the partial reduction of H 2 SO 4 leads to a large amount of defects and minor S doping (ca. 0.55 at%). The expanded graphene oxide with a crumpled form and rich defects was used as electrode materials for the oxygen reduction reaction (ORR), and a very high ORR performance was observed in 0.1 mol L −1 KOH, exhibiting an onset potential of 0.92 V, a half-wave potential of 0.83 V, and a roughly 5.68 mA cm −2 limiting current density with catalyst loading of 0.1274 mg cm −2 . Our work provides reliable GO-based catalyst materials for the ORR; moreover, it will expand the knowledge one type of high-activity site for the ORR: defects on crumpled edges. Graphical In a crump : Defect-rich crumpled graphene oxide (CGO) is fabricated by using a modified Hummers method, followed by fast thermal treatment. Abundant defective and doping sites are created, presenting on the crumpled edges. Highly comparable oxygen reduction reaction performance of the CGO is demonstrated relative to commercial Pt/C.