Graphene Oxides Derivatives Prepared by an Electrochemical Approach

Abstract

Graphene oxide (GO) is a novel material that can be defined as a single monolayer of graphite with oxygen-containing functionalities such as epoxides, alcohols, and carboxylic acids. It is an interesting alternative to graphene for many applications due to its exceptional optical, chemical, and electrical properties. In this study, GOs with different extent of surface groups were prepared by an electrochemical two-stage approach using graphite as raw material. Various synthesis conditions were tested to increase the nanomaterial oxidation level, and the surface topography of the GO derivatives was analyzed via Scanning Electron Microscopy (SEM) and atomic force microscopy (AFM). The electrochemical approach employed in this study maintains the integrity of the graphene sheets, allowing to get large, uniform and well exfoliated GO. A correlation was found between the derivatives properties and their surface topography, interlayer spacing, defect content and specific surface area (SSA). In particular, the electrical resistance decreases with increasing SSA while rises with increasing the D/G band intensity ratio in the Raman spectra, hence the defect content. Understanding the structure-property relationships in these materials is useful for the design of modified GOs with controlable morphologies and properties for a wide range of applications in electrical/electronic devices.