Preparation and characterization of CaO nanoparticles from Ca(OH)2 by direct thermal decomposition method

CaO is an important material because of its application as catalyst and effective chemisorbents for toxic gases. In this research CaO nanoparticles were prepared via direct thermal decomposition method using Ca(OH)(2) as a wet chemically synthesized precursor. Nanocrystalline particles of Ca(OH)(2) have been obtained by adding 1 and 2 M NaOH aqueous solutions to 0.5 M CaCl2 center dot 2H(2)O aqueous solutions at 80 degrees C. The precursor [Ca(OH)(2)] was calcined in N-2 atmosphere at 650 degrees C for 1 h. Samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared spectrum (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunaure-Emett-Teller (BET). SEM images showed that CaO nano-particles were nearly spherical in morphology. TEM images illustrated that produced CaO nano-particles had the mean particle size of 91 and 94 nm for 1 and 2 M NaOH concentration, respectively. As a result, this method could be used for production of CaO nano-particles on large-scale as a cheap and convenient way, without using any surfactant, organic medium or complicated equipment. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.