Synthesis of ZnO nanoparticles by flame spray pyrolysis and characterisation protocol

Abstract

This paper reports detailed characterisation of a zinc oxide (ZnO) nanopowder synthesized by a flame spray pyrolysis method. Detailed characterisation of the powder was carried out following a protocol that aims to determine key physicochemical characteristics that may affect its toxicity. Analysis by X-ray diffraction, (XRD), transmission electron microscopy (TEM) and surface area measurements confirmed monophasic hexagonal wurtzite ZnO nanoparticles with a specific surface area of 59 m 2 /g. Histograms derived from TEM analysis are presented to illustrate the polydispersity within the sample; particles were elongated in the c-crystallographic direction, with average length ~ 23 nm and width ~14 nm.Dynamic light scattering (0.1 w/v % in deionised water, pH 7.4) revealed the particles were agglomerated with a modal secondary particle size of ~ 1.5 μm. Fourier transform infra-red spectroscopy and X-ray photoelectron spectroscopy indicated the presence of carbonate impurities on the surface of the ZnO nanoparticles.

Nanomaterials

“…74 A characterization protocol for ZnO NM has been described which identifies the presence of zinc carbonate and hydroxide impurities on the surface of uncoated ZnO. 75 These impurities probably impact on the dispersion stability and may form from atmospheric contamination 75 or because of the partial solubility and reprecipitation of ZnO in water 76 or certain cell culture media such as Dulbecco's Modified Eagle Medium (DMEM) ( Figure 6). Comparison between DLS and plunge freeze TEM of uncoated ZnO NM dispersed in water and serum protein supplemented water are in broad agreement; serum proteins produce a dispersion of significantly finer agglomerates by providing a size-stabilizing coating or corona on the NM (Figure 4).…”

Parameters for spray drying ZnO nanopowders as spherical granules

“…ZnO nanopowders having different particle size, shape, morphology, and agglomerate structure could be synthesized by various methods like precipitation, 1-8 sol-gel, [8][9][10][11] micro emulsion precipitation, 12 sonochemical, [13][14][15] hydro-and solvothermal, [16][17][18][19][20] thermal decomposition, 21 microwave-assisted techniques, 22 combustion, [23][24][25] spray pyrolysis, [26][27][28][29] chemical or physical vapor deposition. [30][31][32][33] Each method has its advantages and disadvantages based on its complexity and difficulty, cost, mass production in large quantity, powder properties, and environmental effects.…”

“…47,48 The transform of the precursor droplets in an aqueous aerosol form of solutions, emulsions, suspension or slurries into solid powders can be carried out by concurrent atomizing, drying and rapid evaporation of the aerosol droplets in a hot air flow at a certain temperature and pressure. [34][35][36][37][38][39][40][41][42][43][44][45] There are many techniques to obtain finely atomized droplets, for example flame spray reactor, 28 ultrasonic atomizer systems, 26,27,30 spray dryer with a nozzle, electrostatic sprayer, or rotary head. [34][35][36][37][38][39][40][41][42][43][44][45] Spray dryers represent considerable importance for sample preparation at manufacturing of high technology ceramic materials.…”

Rapid, controllable, one‐pot and room‐temperature aqueous synthesis of ZnO:Cu nanoparticles by pulsed UV laser and its application for photocatalytic degradation of methyl orange

“…Among the metal oxide NPs, zinc oxide (ZnO) NPs are of special interest due to wide band gap, non‐toxicity, suitability for doping and their wide range of applications in electronic devices, luminescent materials, sensors, fuel cells, anti‐bacterial action and photocatalysts . A large number of methods are employed to synthesize ZnO NPs at various temperatures and reaction times, which include spray pyrolysis, sonochemical, hydrothermal/solvothermal, sol‐gel, combustion, laser ablation, pulsed laser deposition, ball milling, co‐precipitation and microwave assisted method . In many of them, the main aim is to reduce the cost of synthesis.…”

“…In many of them, the main aim is to reduce the cost of synthesis. It is noteworthy that long reaction time and high reaction temperature‐process are the crucial characteristics of the reported approaches . Therefore it is very important to find a simple, rapid, low temperature method for the synthesis of ZnO NPs.…”