Preparation of graphene sheets
A large number of pure graphene sheets were successfully prepared during the production of non-stoichiometric TiO2 graphene nanocomposites by thermally hydrolyzing the suspension with graphene nanosheets and titanium dioxide peroxidation complexes. Pure graphene nanosheets are made of natural graphite using a high-intensity cavitation field generated by an ultrasonic processor in a 5 bar high pressure ultrasonic reactor. The obtained graphene sheet has a high specific surface area and unique electronic characteristics and can be used as a good carrier for TiO2 to enhance photocatalytic activity. The quality of graphene prepared by ultrasonic waves is much higher than that of graphene obtained by the Hummer method, in which graphite is stripped and oxidized. Since the physical conditions in the ultrasonic reactor can be precisely controlled, and by assuming that the concentration of graphene as a dopant will vary from 1 to 0.001%, graphene can be produced in a commercial scale continuous system.
Ultrasonic Dispersion of graphene oxide
A process for preparing a graphene oxide (GO) layer using ultrasonic radiation. Twenty-five milligrams of graphene oxide powder was suspended in 200 milliliters of deionized water. An uneven brown suspension was obtained by stirring. The resulting suspension was sonicated (30 min, 1.3 x 105 J) and after drying (373 K), sonicated graphene oxide was prepared. FTIR spectroscopy showed that sonication did not alter the functional groups of graphene oxide.