Fabrication and Characterization of Graphene Nanofibers by Electrospinning Technique and Its Electrochemical Properties.

Graphene has proved to be superior material for its exceptional physicochemical 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. Estimated surface area of this material is as high as 526 m²g-1 with pores having size around 20 nm. Specific-capacitance of these nanofibers for current-density of 1 Ag-1 is 144.2 Fg-1, which will be useful for the advancement of devices for storing energy.

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO2 hybrid composite.

A Cu/CuO/porous carbon nanofiber/TiO2 (Cu/CuO/PCNF/TiO2) composite uniformly covered with TiO2 nanoparticles was synthesized by electrospinning and a simple hydrothermal technique. The synthesized composite exhibits a unique morphology and excellent supercapacitive performance, including both electric double layer and pseudo-capacitance behavior. Electrochemical measurements were performed by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The highest specific capacitance value of 530 F g-1 at a current density of 1.5 A g-1 was obtained for the Cu/CuO/PCNF/TiO2 composite electrode in a three-electrode configuration. The solid-state hybrid supercapacitor (SSHSC) fabricated based on this composite exhibits a high specific capacitance value of 330 F g-1 at a current density of 1 A g-1 with 78.8% capacitance retention for up to 10,000 cycles. At the same time, a high energy density of 45.83 Wh kg-1 at a power density of 1.27 kW kg-1 was also realized. The developed electrode material provides new insight into ways to enhance the electrochemical properties of solid-state supercapacitors, based on the synergistic effect of porous carbon nanofibers, metal and metal oxide nanoparticles, which together open up new opportunities for energy storage and conversion applications.

Superior Photocatalytic Performance of CeO2 Nanoparticles and Reduced Graphene Oxide Nanocomposite Prepared by Low Cost Co-Precipitation Method.

In this article, cerium oxide nanoparticles (CeO2 NPs) and reduced graphene oxide nanocomposite have been fabricated through simple, easy and cost effective co-precipitation method. The structural, optical and morphological characterization provides the evidence of successful synthesis of CeO2 NPs and nanocomposite. X-ray photoelectron spectroscopic characterization provides useful information about the concentrations and proportions of Ce3+ and Ce4+ ions in nanoparticles as well as in nanocomposite. These studies provide an insight to understand enhanced photocatalytic activity of nanocomposite. The nanocomposite produces 81% photocatalytic degradation of methyl orange compared to only 45% degradation by CeO2 NPs alone.