Effect of thermal treatment on the synthesis of NiAl sub(2)O sub(4) spinel oxide using chitosan as precursor

• Published in: Cerâmica (São Paulo) Vol. 61; no. 360; pp. 477 - 481
• Main Authors: Anchieta, C G, Tochetto, L, Madalosso, H B, Sulkovski, R D, Serpa, C, Mazutti, M A, de Almeida, A R F, Gundel, A, Foletto, E L
• Format: Magazine Article
• Language: Portuguese
• Published: 01.12.2015
• Subjects: Aluminates; Aluminum; Atomic structure; Chitosan; Heat treatment; Nickel; Oxides; Spinel
• ISSN: 0366-6913; 1678-4553
• DOI: 10.1590/0366-69132015613601925

Nickel aluminate oxide (NiAl sub(2)O sub(4)) was prepared using chitosan as polymeric precursor and ammonia solution as a precipitating agent. In addition, nickel nitrate and aluminum nitrate salts were used as sources of Ni and Al, under stoichiometric amounts (molar ratio Ni:Al = 1:2). NiAl sub(2)O sub(4) particles were prepared at different calcination temperatures and their properties were investigated. The synthesized materials were characterized by X-ray diffraction, infrared spectroscopy, atomic force microscopy, thermogravimetric analysis and nitrogen adsorption-desorption isotherms. The results showed that the thermal treatment process strongly influence on the formation of a single-phase structure of NiAl sub(2)O sub(4) spinel. Nickel aluminate spinel with a porous structure and high surface area was obtained at temperatures above 700 [degrees]C.Original Abstract: Aluminato de niquel (NiAl sub(2)O sub(4)) foi preparado utilizando quitosana como precursor polimerico e uma solucao amoniacal como um agente de precipitacao. Alem disso, sais de nitrato de niquel e de nitrato aluminio foram empregados como fontes de Ni e Al, em quantidades estequiometricas (razao molar Ni:Al = 1:2). Particulas de NiAl sub(2)O sub(4) foram preparadas em diferentes temperaturas de calcinacao e as suas propriedades foram investigadas. Os solidos sintetizados foram caracterizados por difracao de raios X, espectroscopia de infravermelho, microscopia de forca atomica, analise termogravimetrica e isotermas de adsorcao-dessorcao de nitrogenio. Os resultados mostraram que o processo de tratamento termico influencia fortemente sobre formacao da fase espinelio NiAl sub(2)O sub(4). Particulas de aluminato de niquel, com uma estrutura porosa e com alta area superficial, foram obtidas em temperaturas superiores a 700 [degrees]C.