Synthesis and characterization of graphene nanofibers graphene based nanocomposites for energy and environmental applications

Abstract

Graphene a single layer, two-dimensional sheet of sp2 -hybridized carbon, has attracted considerable attention in recent years because of its excellent electrical, thermal, optical and mechanical properties, leading to potential application in different areas, such as photovoltaics, sensors, batteries and nanoelectronics. The study of decorating the graphene sheets with inorganic functional materials such as metals, metal oxides and metal sulfides is now becoming a promising and challenging area of research. Recently efforts have been focused on the synthesis of inorganic materials with different structures on graphene sheets by using the graphene oxide solution. The functional groups such as epoxide, hydroxyl, carboxyl and carbonyl groups were attached to the graphene oxide layer. These functional groups offer the anchoring point of inorganic materials. The main objective of the thesis is to synthesis the rGO nanofibers, NiO/rGO/TiO2, CeO2 nanosheets/rGO composites and CdS/rGO/TiO2 composites without using hazardous reducing agents. The structural, optical, photocatalytic and electrochemical properties have been studied for the prepared composites. Graphene has proved to be superior material for its exceptional physicohemical properties. However engineering graphene macroscopic structures by manipulating microscopic structures has faced a great challenge. Towards this here we report a fabrication method of graphene nanofiber by using simple electrospinning method. Fourier transform infrared and Raman spectroscopic characterizations confirmed the transformation from GO to reduced graphene for the nanofiber material. This material showed high specific surface area of 526 m2 g -1 with pores having size around 20 nm. iv Specific-capacitance of these nanofibers for the current density of 1 Ag-1 is 144.2 Fg-1, which will be useful for the advancement of devices for storing energy. newline