Print version ISSN 0100-4042
TAGLIAFERRO, Geronimo Virginio; SILVA, Maria Lúcia C. P. da and SILVA, Gilberto L. J. P. da. Influence of precipitating agent in the preparation of hydrous niobium oxide by the method of homogeneous precipitation. Quím. Nova [online]. 2005, vol.28, n.2, pp. 250-254. ISSN 0100-4042. http://dx.doi.org/10.1590/S0100-40422005000200016.
This work reports the preparation, characterization and study of the ion exchange behavior of hydrous niobium oxide prepared by a homogeneous precipitation method. The precipitating agent was obtained in aqueous solution by thermal decomposition of urea or ammonium carbonate. The compounds were chemically and physically characterized by X-ray diffractometry, thermal analysis (TG/DTG), surface area measurements and ion exchange behavior with sodium. The materials prepared with ammonium carbonate presented a higher degree of crystallinity and better ion exchange capacity with sodium than materials prepared with urea. In the homogeneous precipitation method, materials were obtained with specific surface area of 123 - 224 m2 g-1. A variation of the preparation process produced hydrous niobium oxide with a different degree of hydration and specific surface area. This provided materials with different physico-chemical properties.
Keywords : hydrous niobium oxide; inorganic ion exchanger; homogeneous precipitation method.