Low-cost and large-scale synthesis of graphene nanosheets by arc discharge inair

Abstract

Large scale production of graphene nanosheets was achieved by arcevaporation of a graphite rod in air. The graphene nanosheets are ∼ 100–200 nm wide and the number of layers is mainly in the range of 2–10. Several tens ofgrams of product were obtained per day. The yield of graphene nanosheets wasfound to be dependent on the pressure of the air, i.e. high pressure facilitates theformation of graphene nanosheets, but low pressure favors the growth of othercarbon nanostructures including carbon nanohorns and nanospheres. Based on thisresult, a pressure-induced mechanism of formation of graphene nanosheets isproposed. The impurities in the products could be eliminated by oxidation in air.