Exfoliation Of Graphite Into Graphene By The Assist Of Metal Catalyst And The Application Of Graphene

Graphene is highly desired for energy storage,printing electronics,catalysis,biomedicine and composites.The“hummers”method for graphene synthesis suffers from environment pollution and explosion danger,which uses amount of strong acid and strong oxidants.It is imperative to develop scalable safe and green approach for graphene large-scale synthesis.Here,we report a one-step strategy of acid-free electrochemical exfoliation of natural graphite flakes into graphene oxide by the assist of OER metal catalyst.The metal anode is used as carrier of natural graphite flakes in the electrolyte for generating local strong acid to increase production efficiency,by which the pH could return normal after turning off the power supply.Moreover,the graphene of different size is filtrated by atomization approach.In this subject,the graphene film which is prepared by vacuum filtration is used as supercapacitor and thermal conductive film.?1?We report a one-step strategy of acid-free electrochemical exfoliation of natural graphite flakes into graphene oxide by the assist of OER metal catalyst.The approach synthesizes graphene with a high yield?>80%?and large lateral size?¹0?m?,in which 91%consists of1³ layers.?2?In order to separate graphene,both the ultrasonic atomization and spray aerosol generator atomized droplets are provided.The graphene within 4 micrometers is filtrated because the atomized droplet size?<5 micrometers?limits the separation size of graphene.Atomization is very effective to filtrate small size graphene.?3?The graphene film which is prepared by vacuum filtration are used as supercapacitor and thermal conductive film.Capacitance of the graphene film is up to 99 F/g.After the high temperature treatment of 3000?thermal conductivity of film(up to 761 W·m^-1·K^-1)is far higher than copper.