Graphene and the production of graphene
Compositions comprising hydrogenated and dehydrogenated graphite comprising a plurality of flakes. At least one flake in ten has a size in excess of ten square micrometers. For example, the flakes can have an average thickness of 10 atomic layers or less.
1. A method for the expansion of the graphite to graphene, wherein graphite particles and at least one electrolyte are introduced into at least one container and the graphite, through the application of an electrical voltage to at least one anode and at least one cathode is expanded, wherein the cathode contains or consists of diamond and hydrogen is produced at the cathode.
2. Method according to claim 1 , wherein hydrogen is intercalated in the graphite particles or chemisorbed on the graphite particles, so that graphene flakes are exfoliated from the graphite particles.
3. Method according to claim 1 , wherein the anode is separated from the cathode by a separator.
4. Method according to claim 3 , wherein the separator contains or consists of one or more of diamond, polytetrafluoroethylene, Al2O3, ceramic, quartz, or glass.
5. Method according to claim 3 , wherein the separator, or both the separator and the anode, are set into rotation.
6. Method according to claim 1 , wherein an electrical voltage from about 5 V to about 60 V is applied between the anode and cathode.
7. Method according to any claim 1 , further comprising the step of photo-treating the graphene flakes for dehydrogenation, wherein more that 50% of hydrogenated sp3 hybridized carbon sites are de-hydrogenated.
8. Method according to claim 1 , further comprising the step of subsequent thermal treatment of the graphene flakes at a temperature from about 100° C. to about 800° C. and for a period of from about 1 min to about 60 min.
9. Method according to claim 1 , wherein the graphene flakes have an average surface area of more than 10 um2.