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

(Efeito do tratamento térmico na síntese do óxido espinélio NiAl₂O₄ usando quitosana como precursor)

Abstract

Nickel aluminate oxide (NiAl₂O₄) 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). NiAl₂O₄ 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 NiAl₂O₄ spinel. Nickel aluminate spinel with a porous structure and high surface area was obtained at temperatures above 700 ºC.

Keywords:
nickel aluminate; synthesis; characterization; chitosan; porous material