ORIGINAL PAPER Fabrication and characterization of copper nanoparticles using thermal reduction: The effect of nonionic surfactants on size and yield of nanoparticles Mohammad Hossein Habibi & Reza Kamrani & Reza Mokhtari Received: 19 March 2010 / Accepted: 8 July 2010 / Published online: 18 July 2010 # Springer-Verlag 2010 Abstract Thermal reduction has been applied to the preparation of copper nanoparticles (Cu-NPs) using three kinds of nonionic surfactants (Triton X-100, Tween-80, and dodecylamine). The Cu-NPs were formed by decomposition of copper(II) oxalate in presence of triphenylphosphine. The effect of the surfactants on the formation of the Cu-NPs was studied via X-ray diffrac- tion, scanning electron microscopy, energy dispersive analysis of X-rays, transmission electron microscopy, thermogravimetric differential thermal analyses, and Fourier transform infra-red spectroscopy. It is shown that the Cu-NPs have an fcc crystal structure. Depending on the surfactant used, Cu-NPs with diameters between 8 and 20 nm can be prepared. The smallest Cu-NPs (8 nm) were formed in the presence of micelles of dodecylamine (yield 49%), while the largest particles (20 nm) were obtained with Triton X-100 (yield 99%). The use of Triton X-100 results in the highest yield and most uniform Cu-NPs. Keywords Copper nanoparticles . Nonionic surfactants . Thermal reduction . Decomposition . Triton X-100 . Tween-80 . Dodecyl amine Introduction Great attention has been paid to metal nanoparticles with extremely small dimensions exhibit novel chemical, optical, and electronic properties. Nanoparticles are interesting materials for catalysis with selectivity, specific activity and unique properties which differ from the bulk properties [1–4]. Among various metal nanoparticles, Cu-NPs are of significant technological interest because of their catalytic, optical and electrical conducting properties [5–8]. Copper nanoparticles are particularly attractive for modern technol- ogies such as metal injection molding, ceramics, electron- ics, thin-film and application in cancer cell killing and germicides. The importance of Cu-NPs is applications as high surface area catalysts that are used in diverse chemical processes [9–12]. In addition, copper particles have applications as catalysts in traditional and new organic syntheses [13–17]. Fabrication of copper particles has been studied by different solution reactions [18–25]. Two attractive ways to aerosol formation of copper particles are via the chemical route and physical methods [26–30]. Niassari et al studied the production of Cu-NPs by thermal decomposition of copper complex [31–33]. Little research has been carried out to synthesis Cu-NPs by thermal decomposition method with controlled sizes and yields. The obvious advantage of this method is the possibility to produce nanoparticles at ambient pressure. This research describes the findings of an investigation of the synthesis of Cu-NPs with controlled sizes, yields and potentially shapes by a selection of proper copper precursor using different nonionic surfactants. Such studies are important for engineering the sizes and shapes of Cu-NPs for potential applications in catalysis and sensors [34, 35]. Copper Electronic supplementary material The online version of this article (doi:10.1007/s00604-010-0413-2) contains supplementary material, which is available to authorized users. M. H. Habibi (*) : R. Kamrani : R. Mokhtari Nanotechnology Laboratory, Department of Chemistry, University of Isfahan, Isfahan 81746-73441, I.R. of Iran e-mail: habibi@chem.ui.ac.ir e-mail: mhhabibi@yahoo.com Microchim Acta (2010) 171:91–95 DOI 10.1007/s00604-010-0413-2