Structural Characterisation of ZnO Particles Obtained by the Emulsion Precipitation Method

Abstract

Zinc oxide was obtained by precipitation in an emulsion system with zinc acetate used as a precursor of ZnO and potassium hydroxide or sodium hydroxide as a precipitating agent. The cyclohexane, as an organic phase, and a nonionic surfactant mixture were also used for preparation of the emulsion. By applying modifications of the ZnO precipitation process, such as changing the precipitating agent, composition of substrates, and the rate of substrate dosing, some interesting structures of ZnO particles were obtained. The morphology of the modified samples was analysed based on SEM (scanning electron microscope) and TEM (transmission electron microscope) images. Moreover the samples were characterised by determination of their dispersive properties using the noninvasive back scattering method (NIBS), adsorption parameters (BET), and crystalline structure (XRD). Thermogravimetric analysis (TG) as well as infrared spectrophotometry (FT-IR) was also applied. For selected samples their electrical properties (dielectric permittivity and electric conductivity) were also measured. The zinc oxide obtained consisted of particles in the shapes of solids, ellipsoids, rods, and flakes, with size ranging from 164 to 2670 nm and showed well-developed surface area with values as high as 20 m2/g.

Comparison of the thermal decomposition processes of several aminoalcohol-based ZnO inks with one containing ethanolamine

“…Unfortunately, the method used to make these measurements (film flakes inside KBr pellets) precludes any attempt of quantification. Consequently, although one can see varying intensities of the carboxylate and (aliphatic) C-H-stretching bonds [21] (inset of Fig.5b) from film to film, from these slight differences one cannot infer higher or lower organic content. Instead, the elemental C and N contents have been quantified by EOA.…”

The effect of concentration ratio and type of functional group on synthesis of CNT–ZnO hybrid nanomaterial by an in situ sol–gel process

“…Many metal oxides and sulfides such as TiO 2 , Cu 2 O, Al 2 O 3 , Co 3 O 4 , MgO, Fe x O y , ZnS and CdS have been used to modify the CNTs [12][13][14][15]. Zink oxide is a semiconductor material with an energy gap of 3.37 eV and a large exciton binding energy (60 meV) at room temperature [16][17][18][19]. ZnO has remarkable physical and chemical properties including nontoxic nature, low cost, high optical activity and stability, high sensitivity of UV-Vis light and high thermal and mechanical stability at room temperature [12,13,16,17,20,21].…”

“…Zink oxide is a semiconductor material with an energy gap of 3.37 eV and a large exciton binding energy (60 meV) at room temperature [16][17][18][19]. ZnO has remarkable physical and chemical properties including nontoxic nature, low cost, high optical activity and stability, high sensitivity of UV-Vis light and high thermal and mechanical stability at room temperature [12,13,16,17,20,21]. These properties revealed that the ZnO is a useful material in electronics, optics, photonics, room temperature UV lasers, light emitting diodes and sensors [10-13, 20, 22].…”

An alternative, faster and simpler method for the formation of hierarchically porous ZnO particles and their thermoelectric performance

“…This was due to the decomposition of carbonates groups and the remaining organic substances (surfactant). 25,30,31 From these results, the endothermic peak and weight loss was attributed to de-carboxylation and de-hydroxylation. 31 For this reason, to satisfy the formation of ZnO structure, calcination was done only at 450 C (see Fig.…”

“…26,30,31 The zinc nitrate hexahydrate solution, precipitant, and surfactants in WP1, WP2, and OP, respectively, were rapidly mixed, ltered and dried. Then the NZnO powders were formed aer annealing at 450 C. These parameters were maintained to achieve the porous structure orientation and particle size distribution of the NZnO powders (see Fig.…”