PREPARATION OF NANOSTRUCTURED HOLLOW-SPHERE FORMED NiO POWDER BY AEROSOL PYROLYSIS METHOD
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Nanostructure; Aerosol pyrolysis; Nickel oxide powder (NiO); X-ray; BET; SEM.Abstract
In this work, the nanostructured hollow-sphere formed nickel oxide (NiO) powder was synthesized via aerosol pyrolysis of 10 wt. % nickel acetate aqueous solution. The effect of pyrolysis temperature on dimensional and morphological characteristics of nickel oxide nanostructured hollow spheres was enlighted. The obtained NiO powder was investigated by methods of low-temperature nitrogen adsorption (BET), X-ray diffraction, scanning electron microscopy (SEM) and particle size class analysis using dynamic light scattering. The results of the study showed that the synthesized product was a single-phase NiO powder with a face-centered cubic structure (fcc) in the form of hollow microspheres ranging in size from 500 nm to 15 μm with a shell thickness of about 100 nm, which consists of nanoparticles with sizes in the range of 5 – 25 nm. Adjusting pyrolysis temperature from 650 to 1150 ºC allows to control the average size of NiO nanoparticles from 5 to 15 nm, reducing the size of hollow spheres, improving the crystalline structure, and also leads to their tendency of transformation from a spherical shape to mushroom caps or an irregular shape. This is a consequence of the intensification of mass- and heat transfer processes at high temperatures.
