Synthesis and characterization of high-quality multi layered graphene by electrochemical exfoliation of graphite

Abstract

Graphene is an emerging carbon material, with wide range of practical applications on a large scale. The yield and quality control of the resultant graphene are significant trade-offs in graphene production. The research is focused on fabricating high quality multi layered graphene using an electrochemical exfoliation approach by adjusting the electrolysis parameters, such as type, composition, concentration of electrolyte and DC Voltage. An aqueous solution of 0.3M (H2SO4) and 30% KOH has been used as an electrolyte. A constant DC voltage supply of +10 V has been incorporated for the electrolysis for investigation of the relationship between characterization and synthesis parameters. The structure, chemical properties and morphology of the synthesized graphene material were investigated using XRD, FTIR, Raman, UV-vis spectroscopy, FESEM, AFM and TEM/HRTEM techniques. FTIR spectrum showed the appearance of C-O and C-OH functional groups, along with C=C stretching of hexagonal network of graphene. The electronic transition of π-π* and n-π* are visible in UV-vis spectra of graphene. XRD pattern of graphene sample exhibits a characteristic peak at 2θ = 26.45, corresponding to a 3.412 Å interlayer distance. The development of multi-layered graphene was demonstrated by the shape and location of the 2D band in the Raman spectra. These studies reveal a comprehensive and detailed morphology showing the wrinkled layered surface with crumpled edges of few layer graphene. Further, this study reinforces the tremendous potential of electrochemical exfoliation for fabricating huge amounts of relatively perfect graphene structures for applications of practical importance.