Hindawi Publishing Corporation Journal of Materials Volume 2013, Article ID 478681, 11 pages http://dx.doi.org/10.1155/2013/478681 Research Article Microwave Assisted Synthesis of ZnO Nanoparticles: Effect of Precursor Reagents, Temperature, Irradiation Time, and Additives on Nano-ZnO Morphology Development Gastón P. Barreto, Graciela Morales, and Ma. Luisa López Quintanilla Centro de Investigaci´ on en Qu´ ımica Aplicada, Boulevard Enrique Reyna 140, 25253 Saltillo, COAH, Mexico Correspondence should be addressed to Gast´ on P. Barreto; gbarreto@fo.unicen.edu.ar Received 27 December 2012; Accepted 26 March 2013 Academic Editor: Antoni Morawski Copyright © 2013 Gast´ on P. Barreto et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te efect of diferent variables (precursor reagents, temperature, irradiation time, microwave radiation power, and additives addition) on the fnal morphology of nano-ZnO obtained through the microwave assisted technique has been investigated. Te characterization of the samples has been carried out by feld emission scanning electron microscopy (FE-SEM) in transmission mode, infrared (FTIR), UV-Vis spectroscopy, and powder X-ray difraction (XRD). Te results showed that all the above-mentioned variables infuencedto some extent the shape and/or size of the synthetized nanoparticles. In particular, the addition of an anionic surfactant (sodium di-2-ethylhexyl-sulfosuccinate (AOT)) to the reaction mixture allowed the synthesis of smaller hexagonal prismatic particles (100 nm), which show a signifcant increase in UV absorption. 1. Introduction ZnO powder has been widely used into numerous mate- rials and products including paints, plastics, ceramics, and adhesives. It is a semiconductor of the II–VI semiconductor group with several favorable properties such as high elec- tron mobility, wideband gap, and strong room temperature luminescence. Tese properties make ZnO an attractive compound for diferent emerging applications. In the last two decades many methods ranging from gas- phase processes to solution routes have been investigated for the synthesis of ZnO nanoparticles including solution precipitation [1, 2], spray pyrolysis [3, 4], hydrothermal synthesis [5–7], sol-gel processes [8–11], and microemulsion synthesis [12]. In cases where the synthesis has been carried out through a conventional thermostatic system, the walls of the reactor are heated by convection or conduction, the core of the sample needs longer time to achieve the target temperature, and this may result in inhomogeneous temperature profles. One possible solution to this problem is the use of microwave heating, which has become a very promising method of syn- thesis for both organic [13, 14], and inorganic [15] chemistry. Tis technique enables the rapid and homogenous heating of the reaction mixture to the desire temperature, which saves time and energy. Te microwave heating is based on two conversion mech- anisms of the electromagnetic radiation into heat energy, namely, dipolar rotation and ionic conduction, which are directly related to the chemistry composition of the reaction mixture. So that, diferent compounds have diferent micro- wave absorbing properties, and this behavior allows a selec- tive heating of compounds in the reaction mixture. Te general advantages of microwave mediated synthesis over conventional ones are (1) reaction rate acceleration as a consequence of high heating rates, (2) wide range of reaction conditions, that is, mild conditions or autoclave conditions, (3) high reaction yields, (4) reaction selectivity due to dif- ferent microwave absorbing properties, (5) excellent control over reaction conditions, and (6) simple handling, allowing simple and fast optimization of experimental parameters.