engleski

Graphene preparation by electrochemical exfoliation of natural graphite flakes

Graphene is an allotrope of carbon, whose structure consists of one-atom thick planar sheets of sp2 bonded carbon atoms that are densely packed in a honeycomb crystal lattice.1 It has excellent properties, including high mobility of charge carriers, unique transport performance, high mechanical strength and extremely high thermal conductivity. Graphene also has a high specific surface area, good elasticity and can offer both optical transparency and high electrical conductivity. These properties render graphene suitable for many applications such as supercapacitors, batteries, composite materials, fuel cells, solar cells, molecular gas sensors and biosensors.1, 2, 3 Various methods have been developed for production of graphene sheets such as epitaxial growth on SiC, chemical vapor deposition, wet-chemical synthesis, mechanical and electrochemical exfoliation of graphite. Electrochemical method is simple, economic, environmentally friendly, operates at ambient temperature and pressure. The process includes anodic or cathodic polarization causing intercalation of ion present in the solution, expansion and exfoliation of graphite. By controlling the intercalation potential it is possible to control the number of layers and surface properties of graphene.3, 4 The aim of this work was electrochemical synthesis of graphene using natural graphite flakes electrode as precursor. In this process 0.1 mol dm-3 sodium dodecyl sulfate (SDS) and 0.1 mol dm-3 sodium dodecyl benzene sulfonate (SDBS) were used as electrolytes. Electrochemical exfoliation of graphite was carried out by applying positive potentials and by intercalation of negative ions. In order to facilitate exfoliation process after anodic ion intercalation negative potential was applied. Obtained product was successfully characterized by employing scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and cyclic voltammetry techniques.

graphene ; exfoliation ; natural graphite flakes

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