Sonochemically Synthesizing of Calcium Compounds Nanostructures

The design and controlled synthesis of nano-structures with different morphological configurations and size distribution on a large scale is very important from the viewpoint of both basic science and technology [1– 4]. CaO is a material having a wide range of applications, being of continuous interest in the field of materials research. CaO is known as dopant able to stabilize cubic zirconia [5] or hafnia [6], and fluently modify the refractive index of silicate glasses [7]. Due to its wide band gap (7.1 eV) [8], high dielectric constant (11.8) [9] and ability to form solid solutions and ternary crystalline phases CaO and their ternary alloys can be considered as interesting dielectric gate materials, exhibiting high mechanical and radiation resistance [10]. Sonochemistry is the research area in which molecules undergo a chemical reaction due to the application of powerful ultrasound radiation (20 KHz-10 MHz) [11]. In the recent years many kinds of nanomaterials have been prepared by this method. In the present work we have developed a simple sonochemical [12] method to prepare CaO nanoparticles, wherein calcium hydroxide is synthesized as a precursor compound by the reaction of calcium acetate and sodium hydroxide (NaOH) in an ultrasonic device and is converted to CaO by heating at 600°C in a furnace. The Ca(OH)2 and CaO nanostructures have been characterized by X-ray powder diffraction (XRD), IR spectroscopy and also the morphology and size of the nanostructures have been observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). We have performed these reactions in several conditions to find out the role of different factors such as the aging time of the reaction in the ultrasonic device and the concentration of the Ca+2 ion on the morphology of the nanostructures.