Spark discharge generation of superparamagnetic Nickel Oxide nanoparticles

The unique properties of superparamagnetic nanoparticles offer many potential applications in various fields, especially in biomedicine. We have synthesized nickel oxide nanoparticles using spark discharge method in the argon gas followed by oxidation at atmospheric conditions. At applied operating conditions, the production rate of the nanoparticles was about 7 mg/h. The produced nanoparticles were characterized in terms of morphology, size, purity, structure, and magnetic property using field emission scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray and electron diffraction, as well as vibrating sample magnetometer analysis. All the characterization techniques suggested the formation of similar to 6nm size nickel oxide nanoparticles and some scarce larger size nickel nanoparticles with a high chemical purity and superparamagnetic behaviour. The results indicate that spark discharge in the gas phase is a facile and powerful method for the generation of chemically pure superparamagnetic nanoparticles as candidate for biomedical applications. (C) 2018 Elsevier Ltd. All rights reserved.