Utjecaj strukture površinski aktivnih tvari na elektrokemijsko raslojavanje prirodnog grafita

The aim of this work was to perform electrochemical exfoliation of natural graphite in order to obtain graphene. The electrolytes (0.1 mol dm-3) were prepared by the dissolution of sodium dodecyl sulfate (SDS) and sodium dodecyl benzenesulfonate (SDBS) in de-ionized water. Graphite electrode was alternately polarized at positive and negative potentials by using two electrode system. During positive polarization SDS and SDBS are intercalated within the structure of graphite, and oxygen evolution as well as carbon oxidation takes place. By applying negative potential cations are intercalated into graphite working electrode and also hydrogen evolution takes place. Electrodes were characterized by using cyclic voltammetry and the exfoliation process was followed by monitoring current transients. The exfoliated products were characterized by employing UV/Vis spectrophotometry and atomic force microscopy. The brown color of the electrolyte indicates that the graphite was exfoliated and UV/Vis spectra of graphene/SDS suspensions has proved that obtained product was graphene oxide. Atomic force microscopy has shown that bi- or trilayer graphene was present within the solution.