Anionic Electrochemical Exfoliation of Few-Layer Graphene Nano-Sheets: An Emphasis on Characterization

Abstract

Graphene, the most unique member of carbon family has fuelled a huge interest across the globe with its superior mechanical, chemical, optical and electronic properties. It has opened enormous avenues for humankind in terms of different applications. Since its discovery in 2004, people have tried various techniques to extract graphene, such as mechanical exfoliation, chemical exfoliation, epitaxial growth, CVD (chemical vapour deposition) etc. However, the above methods are not optimal for mass production, neither are they simple and cost effective. The present work highlights synthesis of graphene through electrochemical approach and its subsequent characterization. Pyrolytic graphite is subjected to intercalation of two different concentrations of HNO3 electrolyte. XRD, FESEM and TEM were utilised to understand the structure and morphology of the obtained few-layer graphene nanosheets (FLGNs). Scanning probe spectroscopy is a useful technique for understanding the morphological structure of a sample at atomic level. Authors have utilised AFM which shows the thickness of the FLGNs to be in the range of 5-6 nm. STM studies of graphene nanosheets revealed atomic scaled periodicity and atomic flatness.