Optical and thermal properties of precursor-controlled graphene–zinc nanocomposites Kanika Anand a , Manmeet Pal Singh b , Onkar Singh a , Nipin Kohli a , Ravi Chand Singh a,n a Department of Physics, Guru Nanak Dev University, Amritsar 143005, India b Khalsa College of Engineering and Technology, Ranjit Avenue, Amritsar 143001, India article info Available online 12 July 2013 Keywords: Graphene Zinc oxide Nanocomposite Hydrazine monohydrate abstract Graphene, a monolayer two dimensional carbon sheet can be utilized as a support to anchor functional nanomaterials to form novel nanocomposites for a variety of potential applications. We present an approach for the in situ preparation of graphene–zinc oxide nanocomposites through a reflux process in which either zinc acetate or zinc chloride can serve as precursors. The synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray analysis, ultraviolet– visible spectroscopy and thermogravimetry analysis (TGA–DSC) for structural, optical and thermal properties. It has been found that nanocomposites comprise of zinc oxide (ZnO) nanostructures deposited on graphene sheets, and the choice of zinc precursor has a deterministic influence on the morphology, structure and properties of the graphene–ZnO nanocomposites. In addition, the novel structure of zinc acetate based nanocomposite has induced improved absorption and thermal stability of the graphene/ZnO nanocomposite as compared to zinc chloride based nanocomposite and would be promising for future applications in nanotechnology. & 2013 Elsevier Ltd. All rights reserved. 1. Introduction Novoselov et al. in 2004 announced a remarkably simple method for preparing monolayer graphene and described some highly innovative experiments that enticed material science community to plunge into this avenue of research [1]. Discovery of this two dimensional (2-D) unique conjugated structure opened a new channel for technological devices and biofuntionalization due to its superb electrical, thermal, optical and mechanical proper- ties [2–6]. Due to 2D layered structure of sp 2 hybridized carbon atoms, graphene exhibits excellent electron accept- ing and electron transport capabilities [7]. It has been established that its composites with metal oxide nanomaterials are attracting more and more interest as the integration of two components in the new hybrid material presents certain desirable features useful in practical applications [8,9]. Among these semiconductors, zinc oxide is a promising material because of its wide band gap (3.37 eV) [10], efficient photocatalysis under UV light irradiation [11], high electron mobility [12] and ability to form wide variety of nanostructures [13]. Therefore an innovative research has been carried out by many research groups to synthesize graphene–zinc oxide nanocomposites and investigate their possible applications. Zheng et al. prepared graphene sheets with pyramid like morphologies on the zinc oxide (ZnO) nanowires coated with Ni catalyst by plasma enhanced chemical vapor deposition with greatly improved field emission property [14]. Kim and coworkers reported the vertical growth of ZnO nanostruc- tures on graphene layers using organic vapor epitaxy and demonstrated a novel transparent and flexible optoelectronic Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/mssp Materials Science in Semiconductor Processing 1369-8001/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.mssp.2013.06.013 n Corresponding author. Tel.: +91 9914129939. E-mail address: ravichand.singh@gmail.com (R.C. Singh). Materials Science in Semiconductor Processing 16 (2013) 1706–1712