Size- and Shape-Control of Crystalline Zinc Oxide Nanoparticles: A New Organometallic Synthetic Method

Abstract

A novel organometallic synthetic method has been developed for the preparation of crystalline ZnO nanoparticles of controlled size and shape. Isotropic nanoparticles with a mean size between 3 and 6 nm and nanorods with a mean diameter of 3–4 nm and length up to 120 nm have been obtained in this way. This synthetic method takes advantage of the exothermic reaction of the precursor Zn(c‐C6H11)2 (1) toward moisture and air and involves the presence of long‐alkyl‐chain amines as stabilizing ligands. The influence of the different experimental parameters (concentration, solvent, nature of the ligand, time, and temperature) on the size and shape of the ZnO nanoparticles has been studied, together with the mechanism of their formation, by NMR spectroscopy, transmission electron microscopy, and X‐ray diffraction techniques. The nanoparticles prepared in this way can be dissolved in most of the common organic solvents, forming colloidal solutions. The surface state of the nanoparticles as well as the possibility of forming luminescent solutions from which regular monolayers can be deposited are also reported.

Organometallic Nanoparticles of Metals or Metal Oxides

“…15). It is demonstrated by NMR that the ligand coordinates on the zinc precursor as well as on the oxide nanoparticles and therefore is probably present throughout the oxidation process [91]. The same reaction carried out using a mixture of long chain amines and long chain carboxylic acids as stabilizers produces monodisperse spherical nanoparticles in the 3-4 nm range which self-organize into 2-D or 3-D super-lattices depending upon the nature of the ligands [92].…”

Lithium ion as growth-controlling agent of ZnO nanoparticles prepared by organometallic synthesis

“…Moreover, all diffractograms display additional peaks in the 2-301 2y range (not shown here) that can be ascribed to the octylamine ligand used during the synthesis as previously reported. 41 No crystalline hydroxide phase or lithium or sodium oxide phase is observed. Moreover, as the Li amount increases, a broadening of the ZnO diffraction peaks is observed whatever the Li precursor (see Fig.…”

“…41,42 It consists in the addition of Zn(c-C 6 H 11 ) 2 solid to a THF solution containing the lithium (sodium) precursor and octylamine (OA) as stabilizer. The proportion of Li (Na) was varied from 1 to 10 mol% compared to Zn.…”

“…28,29,37 In previous works, we evidenced the interest of an organometallic synthesis based on the Zn(c-C 6 H 11 ) 2 complex for the preparation of ZnO nanoparticles of controlled size and shape. 41,42 This method takes advantage of the exothermic reaction of the organometallic precursor with water, the kinetics of which is well controlled by the ligand present in the reaction solution. Importantly, this method only leads to the formation of ZnO nanoparticles and cyclohexane.…”

Oxygen and light sensitive field-effect transistors based on ZnO nanoparticles attached to individual double-walled carbon nanotubes

“…Embedded transition metals can also turn ZnO into a diluted magnetic semiconductor with applications in spintronics [4][5][6]. The growth of ZnO as nanoparticles (NPs) allows size, shape and surface control providing customized material for various applications [7,8]. The synthesis in alcoholic solutions yields stable colloidal suspensions of ZnO nanoparticles with diameters in the range of a few nanometres.…”