Sundara Ramaprabhu

The present work describes the synthesis of cobalt oxide nanoparticle decorated hydrogen exfoliated graphene (Co 3O 4/HEG) by exfoliating graphite oxide in hydrogen atmosphere followed by chemical reduction of cobalt salt using sodium borohydride. The synthesized material has been characterized by X-ray diffractometry, thermogravimetric analysis, field emission scanning electron microscopy and transmission electron microscopy. A flexible field emitter has been fabricated by spin coating this material on carbon cloth. Electron emission characteristics of Co 3O 4/HEG have been investigated using an in-house fabricated setup and analyzed using Fowler-Nordheim equation. Turn-on and threshold fields of 1.12 and 1.35 V μm -1, respectively have been observed for this material. Moreover, the present field emitter shows a reasonably good stability and repeatability. © 2012 Elsevier B.V. All rights reserved.

The two dimensional (2D) graphene is the rising star in the field of nanotechnology among scientific community because of its exceptional properties. Single layer of graphene is having peculiar properties like high electrical and thermal conductivity, good ballistic transport, chemical inertness, and so on [1, 2]. In 2004, Geim and Novoslev have successfully extracted and characterized single layer of graphene by micro mechanical cleavage [3]. After that, different techniques have been developed for small scale and large scales synthesize of single layer and few layer (2-5 layer) graphene. The different methods of synthesize of graphene include thermal exfoliation [4], hydrogen induced exfoliation of graphite oxide (GO) [5], chemical vapor deposition [6], and so on. Depending on the way in which graphene synthesis, the numbers of layers as well as properties of graphene change.