Facile preparation and characterization of α-aluminum oxide particles by ultrasonic spray pyrolysis

Abstract

The microscopic morphology and purity of alumina are crucial factors in determination of its practical applications in high-tech industries such as ceramics, bioceramics, catalyst carriers, and others. In the present paper, α-Al₂O₃ particles were produced by ultrasonic spray pyrolysis employing the Al(NO₃)₃·6H₂O and AlCl₃·6H₂O precursors. The results of microscopic examinations, mapping investigation, and X-ray diffraction (XRD) patterns revealed that alumina formed separated hollow spherical particles with an averaging 0.8 -1.0 µm in size. The sizes of the experimentally acquired alumina particles were contrasted with the theoretically calculated values. The optimal parameters for alumina production such as the precursor concentration and the phase transition temperature were determined to be 1.0 M and 1223 K, respectively. Fourier transform infrared spectroscopy (FT-IR) confirmed that the γ- phase was converted to the α-Al₂O₃ phase. In addition, energy dispersive X-ray (EDX) and X-ray fluorescence (XRF) measurements were utilized to determine the chemical composition of the alumina powder samples, which revealed that the produced α-Al₂O₃ had purities of 99.9 and 99.8 %, respectively, at a sintering temperature of 1473 K. These results provide significant insights for industrial applications in the aforementioned sectors.