Preparation, characterization and applications of graphene and its composites

Abstract

The preparation, characterization and applications of graphene and its composites are investigated in this thesis. Solar exfoliation, a relatively simple and viable method, is used for the production of the reduced graphene oxide. The prepared graphene oxide is tested for applications in supercapacitors and electrochemical sensor for hydrogen peroxide, which is an important chemical species in the biological systems. Later on, vanadium oxide –graphene composite has been prepared and characterized. The prepared composite has been used as sensor for dopamine detection at nanomolar range, a neurotransmitter which can be vital in finding the irregularities related to Alzheimer’s detection. A better performance in terms of lower detection limit (0.07 µM) and sensitivity (25.02 µA mM-1 cm-2) is reported. Also, Lithium ion batteries are fabricated using the prepared composites and the composite offers a good capacitance of around 200 Fg-1. The fifth chapter describes the preparation of zinc oxide - graphene composites. The electrochemical sensor fabricated using zinc oxide - graphene oxide composite was found to be sensitive towards glucose, which is important in the control of diabetes mellitus. Also, supercapacitors electrodes were fabricated and tested using above composites reveals promising performance with hghest specific capacitance of 635 Fg-1.