Electrolyte effect in electrochemical exfoliation of graphite

Exfoliated graphene has been successfully synthesized using electrochemical exfoliation method followed by sonication of the graphite rod. Ammonium sulfate, sodium sulfate, ammonium oxalate, hydrogen peroxide, and ammonium persulfate were used as electrolytes. The effect of sonication time was studied for several products. The exfoliated graphene (EG) was characterized using XRD, Raman, FTIR, SEM-EDS, TEM and electrical conductivity measurement. The exfoliation using ammonium sulfate-ammonium persulfate as the electrolyte gives the highest mass-product, with a yield of almost 70%. Adding peroxide to the electrolyte reduces the mass of the exfoliated product. In addition, different sonication times results in different phenomena of particle size changes. The XRD data show that the EG has 2θ = 26.4° which is lower than its origin graphite. Raman data confirm that the EG has been obtained with the FWHM (G) value of 45–70 cm−1, and the resulting EG is a multilayer (2D peak). The O–H and C–C aromatic group has been assigned from FTIR spectrum. From SEM and TEM images, it was understood that the morphology of material is wrinkled, crumpled, and has a transparent zone, while from EDS data, it is found that the O/C value is in the range of 0.15–0.35. The electrical conductivity of EG reaches 52 S/cm.