%0 Journal Article
%T Optical Property Characterization of Novel Graphene-X (X=Ag, Au and Cu) Nanoparticle Hybrids
%A Sumit Ranjan Sahu
%A Mayanglambam Manolata Devi
%A Puspal Mukherjee
%A Pratik Sen
%A Krishanu Biswas
%J Journal of Nanomaterials
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/232409
%X The present investigation reports new results on optical properties of graphene-metal nanocomposites. These composites were prepared by a solution-based chemical approach. Graphene has been prepared by thermal reduction of graphene oxide (GO) at 90¡ãC by hydrazine hydrate in an ammoniacal medium. This ammoniacal solution acts as a solvent as well as a basic medium where agglomeration of graphene can be prevented. This graphene solution has further been used for functionalization with Ag, Au, and Cu nanoparticles (NPs). The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to reveal the nature and type of interaction of metal nanoparticles with graphene. The results indicate distinct shift of graphene bands both in Raman and UV-Vis spectroscopies due to the presence of the metal nanoparticles. Raman spectroscopic analysis indicates blue shift of D and G bands in Raman spectra of graphene due to the presence of metal nanoparticles except for the G band of Cu-G, which undergoes red shift, reflecting the charge transfer interaction between graphene sheets and metal nanoparticles. UV-Vis spectroscopic analysis also indicates blue shift of graphene absorption peak in the hybrids. The plasmon peak position undergoes blue shift in Ag-G, whereas red shift is observed in Au-G and Cu-G. 1. Introduction Graphene is a unique allotrope of carbon characterized by honeycomb lattice of sp2-hybridized carbon atoms in which carbon atoms are packed in a two-dimensional (2D) hexagonal lattice [1]. Graphene, often considered as a ¡°miracle material¡± of the 21st century, has attracted tremendous attention in the academic community [2]. Being one-atomic layer thick sheet of carbon extending infinitely in 2D, its properties encompass range of superlattices. This includes high value of Young¡¯s modulus (~1100£¿GPa) [3], fracture strength (125£¿GPa) [3], thermal conductivity (~5000£¿W/mK) [4], mobility of charge carriers ( £¿cm2/Vs) [5], and specific surface area 2630£¿(m2/g) [6]. Owing to its excellent physical and chemical properties, graphene is considered as a potential candidate for large number of applications in many technological fields such as nanoelectronics [7], composites [8], energy storage devices [6], efficient lasers, photodetectors, and biomedical applications [9]. Preparation of high quality graphene is needed to study the unique properties for applications. A number of different ways of preparing graphene have been reported in the literature
%U http://www.hindawi.com/journals/jnm/2013/232409/