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

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 20; no. 6; pp. 1713 - 1721
• Main Authors: Ghasemi, Leila, Jafari, Hassan
• Format: Journal Article
• Language: English
• Published: Sao Carlos Universidade Federal do Sao Carlos, Departamento de Engenharia de Materiais 01-11-2017; ABM, ABC, ABPol; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Chelating agents; Chelation; Crystallization; ENGINEERING, CHEMICAL; Evolution; Field emission microscopy; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; Morphology; Nanomaterials; Particle size distribution; Pechini; Polyethylene glycol; Scanning electron microscopy; Sol-gel; Sol-gel processes; Tungsten oxides; Tungsten trioxide; X ray powder diffraction; Nanomaterials; Pechini; Sol-gel; Morphology; Tungsten trioxide
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2017-0467

Sol-gel modified Pechini's method was used to prepare WO3 nanopowders using dicarboxylic acid and polyethylene glycol as the chelating agent and polymeric source, respectively. WO3 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 WO3 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.