19^th European Organic Chemistry Congress

Biography

Biography: Ghulam Abbas

Abstract

The electrochemical processes in two dimensional (2D) materials have a serious impact on their properties encompassing their structural integrity and electronic structure. However, it is difficult to discriminate the roles of the basal plane, edges, defects, or interlayer space in the complex interplay between the material’s properties and the electrochemistry. Also, the electrochemical response at the electrode/electrolyte and the effect of ions at the interface cannot be monitored precisely. The common methods do not allow for simple access to the particular area of a sample, and thus, the spatial resolution is low and there is no distinction between the role of the individual constituents.

Here we show that in-situ Raman microspectroscopy combined with electrochemical analysis provides a powerful method for gaining simultaneous information on the structure and electronic properties of the electrochemically gated 2D material in concentrated aqueous electrolytes. This technique enabled us to discriminate the localized charge transfer process between an electrolyte and graphene in the defect enrich domain within the localized area of 10-20 µm². The defects were produced within a graphene monolayer using an oxygen plasma by changing the exposure time from 0-30 sec. The localized in-situ spectroelectrochemical studies enabled us to monitor the gradual change in graphene doping in the samples for different time exposures to oxygen plasma. The charge transfer was found to occur between the electrolyte and graphene through the defects at the covalently bonded oxygen functional groups. The study provides important knowledge of the local interfacial structure and electrostatic gating at a potentiostatically controlled electrode material, which is of fundamental and technological importance for many electrochemical, chemical and industrial applications.