Journal of Alloys and Compounds 459 (2008) 537–542 Synthesis and characterization of CuO flower-nanostructure processing by a domestic hydrothermal microwave D.P. Volanti a , D. Keyson b , L.S. Cavalcante c,∗ , A.Z. Sim ˜ oes a , M.R. Joya d , E. Longo a , J.A. Varela a , P.S. Pizani d , A.G. Souza b a Laborat´ orio Interdisciplinar em Cerˆ amica, Departamento de F´ ısico-Qu´ ımica, Instituto de Qu´ ımica, Universidade Estadual Paulista, P.O. Box 355, 14801-907 Araraquara, SP, Brazil b Laborat´ orio de Ensino de Ciˆ encias e Laborat´ orio de Combust´ ıveis e Materiais, Departamento de Qu´ ımica, Universidade Federal da Para´ ıba, 58051-900 Jo˜ ao Pessoa, PB, Brazil c Laborat´ orio Interdisciplinar de Eletroqu´ ımica e Cer ˆ amica, Departamento de Qu´ ımica, Universidade Federal de S˜ ao Carlos, P.O. Box 676, 13565-905 S˜ ao Carlos, SP, Brazil d Departamento de F´ ısica, Universidade Federal de S˜ ao Carlos, P.O. Box 676, 13565-905 S˜ ao Carlos, SP, Brazil Received 27 March 2007; received in revised form 7 May 2007; accepted 8 May 2007 Available online 22 May 2007 Abstract The synthesis and characterization of CuO flower-nanostructure processed in domestic hydrothermal microwave oven was presented. Phase anal- ysis was carried out using X-ray diffraction (XRD) and micro-Raman scattering (MRS) and the results confirmed the CuO flower-nanostructure as a single-phase. The field-emission scanning electron microscopy (FEG-SEM) was used to estimate the average spheres diameter while transmission electron microscope (TEM) to observe the thorn of the flower-nanostructures. The mechanism of CuO flower-nanostructures formation is proposed and explained. © 2007 Elsevier B.V. All rights reserved. Keywords: Nanostructured materials; Oxide materials; Nanofabrications; Microstructure; Scanning electron microscopy 1. Introduction In past times, the chemical synthesis of inorganic materials with unusual and novel morphologies has attracted considerable attention because of their potential applications in various fields such as catalysts, medicine, electronics, ceramics, pigments, and cosmetics [1–4]. In particular, the hierarchical structure is one of the important forms among various morphologies [5,6]. Recently, copper oxide-nanostructured materials, such as: nanorods [7], nanowires [8], nanoribbons [9] and nanobelts [10], have attracted considerable attention due to their fundamental importance and potential future applications. This material presents several applications and many efforts have been made to synthesize cupric oxide nanoparticles. For ∗ Corresponding author. Tel.: +55 16 3361 5215; fax: +55 16 3351 8350. E-mail address: laeciosc@bol.com.br (L.S. Cavalcante). example, Brookshier et al. [11] prepared CuO nanoparticles by spin coating technique controlling SiO 2 size. Huang and Mati- jeric [12] reported copper-II-oxide sols of definite size and shape in aqueous solutions. Clay and Cohen [13] synthesized CuO nan- oclusters within films of diblock copolymers. Lisiecki and Pileni [14] produced Cu and CuO nanomaterials from inverse micelle solutions. Recently, CuO in polypyrole synthesized by the metal- organic decomposition (MOD) technique was also reported [15]. In particular, a variety of CuO nanostructures have been prepared by high-temperature approaches [16]. Hydrothermal method has gained space as a versatile method for preparation of copper oxide in temperatures ranging from 373 to 473 K for different times [17–20]. In this paper, we report the preparation of CuO flower- nanostructures by hydrothermal microwave and its characteri- zation by X-ray diffraction (XRD) and micro-Raman scattering (MRS). The morphology of microspheres CuO was observed by 0925-8388/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2007.05.023