Morphological Characterization of Tungsten Trioxide Nanopowders Synthesized by Sol-Gel Modified Pechini's Method

Abstract

Sol-gel modified Pechini's method was used to prepare WO 3 nanopowders using dicarboxylic acid and polyethylene glycol as the chelating agent and polymeric source, respectively. WO 3 powders were first prepared by calcination of resin precursor at 550ºC under various initial concentrations of metal ion (12.5-50 mmol), acid (125-500 mmol), a complexing agent (32-262 mmol), and polyethylene glycol (1-16.5 mmol) in the air atmosphere. The products were characterized using X-ray powder diffraction, field emission scanning electron microscopy, and energy dispersive spectroscopy. The results revealed that the WO 3 nanopowders prepared with different amounts of chelating agent and polyethylene glycol, crystallized in monoclinic phase. The nanopowders were impurity-free due to the presence of the complexing agent and polyethylene glycol as carbon sources. Morphological evolution indicated that the nanopowders evolved from rod-like to regular and spherical shapes, depending on complexing agent and polyethylene glycol amounts. Nanopowders with an average particle size of approximately 58 nm and a narrow size distribution were obtained.

Synthesis of WO3 Nanostructures and Their Nanocomposites with Graphene Derivatives via Novel Chemical Approach

“…The results obtained demonstrate the growth in the size of the crystallites of WO 3 as a function of the annealing temperature. Gui et al synthesized WO 3 with monoclinic phase using the hydrothermal route and WCl 6 as a precursor, they estimated a particle size of the order of 22 nm [18]. Fu et al reported a value, similar to our result, of around 42 nm hydrothermally treated at 180°C for 24 h, using Na 2 WO 4 .2H 2 O as a precursor [19].…”

Influence of the Microwaves on the Sol-Gel Syntheses and on the Properties of the Resulting Oxide Nanostructures

“…The regular method resulted in larger (58 nm) rod-like nanoparticles. The case of the WO 3 particle's crystallinity is similar to the thin layer's: without after annealing process, the MW assisted method provides better crystallinity [65].…”

Binary Metal Oxide Adsorbed Graphene Modified Glassy Carbon Electrode for Detection of Riboflavin

“…Pure WO 3 was prepared by simple sol‐gel method [70]. In brief, 50 mM of sodium tungstate dihydrate was dissolved in 25 mL of water and the solution was stirred for 1 h. Later, 0.5 g of PEG and 1.5 g of oxalic acid were added to the above solution, stirred and heated at 80 °C for 1 h. The solution was kept under agitation for 24 h. The final solution was washed with water and ethanol and dried at 60 °C for 2 h. The obtained hydroxide powder was kept under calcination at 450 °C for 2 h to obtain white powdered tungsten trioxide.…”