6 Synthesis of Nanosized Copper Oxide by Assimilating Microwave Radiation and its Characterizations K. Vijayashree, K. Sheshappa Rai*, T. Demappa* Department of Post-graduate Studies and Research in Polymer Science, University of Mysuru, Sir M Visvesvaraya Post-graduate Centre, Tubinakere, Mandya - 571 402, Karnataka, India. Received 6 th February 2016; Revised 3 rd May 2016; Accepted 15 th May 2016 ABSTRACT Copper oxide (CuO) nanoparticles have been successfully synthesized by microwave assisted - precipitation technique. In terms of advanced nanostructure synthesis, microwave method in which copper hydroxide nanostructures are produced in the precursor solution and sequentially transformed by microwave into CuO may be considered as a promising method. To explore, the blend of two methods adopted was very simple and reliable. This gives a large scale production of CuO nanoparticles easily with a brilliant band gap of 1.55 eV. This method produces not only large quantities of nano yield in a short reaction time but also high-quality materials with advanced properties. The structural, morphological, and optical properties of CuO nanoparticles have been studied and reported. Key words: Nanoparticles, Band gap, Morphology, Metal oxides nanostructures, Microwave assimilation. 1. INTRODUCTION The metal oxides are major class of semiconductors. Copper oxide (CuO), is a well-known p-type semiconducting metal oxide among them, having narrow band gap. The results of earlier works focused on the synthesis and applications of this nanomaterial in several felds [1-6], in various morphologies [7-10], and different preparation methods [11-14]. Along with these methods, microwave-assisted synthesis is typically quite fast, simple, and energy-effcient. The power, heating time, and irradiation cycles are the key parameters of a microwave oven and each of them may have a strong effect on the structure and properties of the products. To the best of our knowledge, there have been few reports on the synthesis of CuO nanopowder which have considered the potential relations between the microwave power and the morphology of materials [15]. In this work, feather-like morphologies of CuO nanopowder were obtained by microwave- assisted synthetic route, using copper sulfate as the precursor without any surfactant and sodium hydroxide as stabilizing agent. The phase, structures, and morphologies of the as-prepared products were investigated by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Optical properties have been studied by ultraviolet-visible (UV-Vis) spectrophotometer. 2. EXPERIMENTAL 2.1. Synthesis of CuO Nanopowder Analytical grade of cupric sulfate pentahydrate (CuSO 4 ·5H 2 O) and sodium hydroxide (NaOH) were purchased from Loba Chemie Pvt. Ltd., Mumbai, India. It has been used as precursors and stabilizing agent, respectively. Double distilled water was used as solvent. In a typical reaction, 0.5 M sodium hydroxide solution was added dropwise to 0.1 M of copper sulfate aqueous solution in the ratio of 1:3 and stirred for 15 min. The resulting solution is kept in a domestic microwave oven (operated with frequency 2.45 GHz and power 800 W) for 10 min and cooled down to room temperature. The obtained colloidal precipitate is black in color. The fnal product was separated by centrifugation, washed with distilled water, and absolute ethanol 4-5 times. In the end, acetone washing is used to remove the organic impurities and then dried at 40°C for 24 h. 3. RESULTS AND DISCUSSION 3.1. XRD Analysis XRD pattern of synthesized CuO nanoparticles is shown in Figure 1. It gives a single-phase monoclinic structure. The obtained parameters are a = 4.683 Å, b = 3.473 Å, and C = 5.122 Å with volume cell of 82.14 Å. 10 distinct diffraction peaks can be seen at 2θ values of 32.56, 35.59, 38.82, 48.24, 53.50, *Corresponding Authors: E-mail: ksheshapparai@gmail.com E-mail: tdemappa2003@yahoo.co.in Indian Journal of Advances in Chemical Science Available online at www.ijacskros.com Indian Journal of Advances in Chemical Science S1 (2016) 6-9