Submicrometer zinc oxide particles: Elaboration in polyol medium and morphological characteristics

Abstract

A novel and easy route for preparing submicrometer particles of zinc oxide, involving hydrolysis of zinc salt in a polyol medium, is proposed. Zinc acetate dihydrate and diethyleneglycol appear to be the best candidates for obtaining a high yield of particles with well-defined morphological characteristics. Monodisperse spherical particles in the submicrometer range (0.2-0.4 /u,m) have been obtained for a salt concentration less than 0.1 mol I"1. The particle size depends mainly on the heating rate. The particles are microporous (surface area: 80 m2 g"1) and are formed by aggregation of small crystallites (10 nm). Calcination at moderate temperature drastically reduces this porosity without significant interparticle sintering. At higher concentration, no aggregation occurs and tiny single crystallite particles are obtained.

Hierarchical structures of ZnO spherical particles synthesized solvothermally

“…Zinc acetate anhydride (2.202 g) and HMT (1.682 g) were each dissolved in 20 ml of an EG-water mixture; they were then mixed and heated at 95 • C for 12 h. Spherical ZnO particles were obtained at 95 • C when the solvent contained 87.5 or 95 vol.% EG. These ZnO spheres were obtained at lower temperatures than in previous reports (150−200 • C) [29][30][31][32][33][34][35][36][37]. This is an advantage of combining the synthesis with the homogeneous precipitation, where hydrolysis is promoted by the decomposition of HMT.…”

“…Various conditions have been used in the glycol-assisted solvothermal synthesis of ZnO particles with hierarchical structure [27][28][29][30][31][32][33][34][35][36][37][38][39], and the concentration of glycol was found to play a key role in the microstructure of ZnO particles. Table 1 lists the preparation conditions of spheroidal ZnO particles using EG and DEG, and the scanning electron microscopy (SEM) images of ZnO particles are shown in figure 3.…”

“…In 1995, Jézéquel et al [29] reported the first synthesis of ZnO spherical powders in glycols. They used zinc acetate dihydrate and DEG.…”

Size dependent fluorescence spectroscopy of nanocolloids of ZnO

“…13,14 The monodisperse ZnO colloidal spheres are produced by a two-stage reaction process. The method of preparation involves the hydrolysis of zinc acetate dihydrate ͑ZnAc; Merck͒ in diethylene glycol medium ͑DEG; Merck͒.…”

Synthesis of ZnO nanoparticles by flame spray pyrolysis and characterisation protocol

“…Nanoparticles of ZnO have been prepared by physical methods, such as milling and grinding, (Shen 2006); by thermal evaporation of ZnO (Wang, 2004) or evaporation and oxidation of zinc (Wu et al, 2000); and by chemical solution synthesis routes such as hydrothermal synthesis (Suchanek, 2009;Baruah and Dutta 2009), sol-gel (Meulenkamp 1998;Mondelaers et al, 2002) and precipitation from both aqueous and non-aqueous solvents (Jézéquel et al, 1995, Hsieh et al, 2007. However, despite the wide variety of wet chemical methods, the majority of ZnO is produced in industry by gas phase synthesis through oxidation of Zn vapour (Auer et al, 2009).…”