A Catalytic Microwave Process for Superfast Preparation of High-Quality Reduced Graphene Oxide

Herein we report that a small amount of graphite can unexpectedly act as the catalyst to greatly promote the microwave exfoliation and reduction of graphite oxide in ambient air. The reaction can be finished in a few seconds in contrast to more than ten minutes without catalyst. The catalytic microwave exfoliated graphite oxide (CMEGO) is of higher quality than the traditional microwave exfoliated graphite oxide, including a much higher exfoliation degree with thinner graphene sheets and higher specific surface area (886 m²  g^-1 vs. 466 m²  g^-1 ), a much larger C/O ratio (19.4 vs. 6.3) and a higher lattice crystallinity, as well as significantly improved electrical conductivity (53180 S m^-1 vs. 5140 S m^-1 ). The CMEGO is used as anode for lithium-ion battery (LIB) and sodium-ion battery (SIB), and delivers ultrahigh reversible capacities, remarkable rate capabilities, and superior cycling stabilities in both LIB and SIB.