Synthesis of Cerium Dioxide Nanoparticles by Gas/Liquid Pulsed Discharge Plasma in a Slug Flow Reactor

[Image: see text] Cerium dioxide (CeO(2)) nanoparticles have gained immense attention owing to their use in various applications. Current synthesis methods for CeO(2) nanoparticles including hydrothermal and chemical precipitation are time-consuming and require chemical reagents. In order to shorten the reaction time and avoid the use of organic reagents, a new method for CeO(2) nanoparticles synthesis in a slug flow system by atmospheric-pressure pulsed discharge plasma was proposed, which provided an easy, efficient, and continuous reaction at room temperature. Cerium nitrate was used as a feed solution, and starch was added as a stabilizer to separate the nucleation and growth processes of the nanoparticles to prevent their aggregation. The system was powered by a high voltage of 10.0 kV (peak-to-peak) from an ac power supply. The products were characterized by transmission electron microscopy (TEM), high-resolution TEM, energy-dispersive X-ray spectroscopy, and UV–vis spectroscopy. The results showed that when a circular capillary glass tube coil was used as the slug flow reactor, the amount of the CeO(2) nanoparticles increased compared to the case when a straight glass tube was used. The size also increased from 3.4 to 6.3 nm. The synthesis mechanism of the CeO(2) nanoparticles by gas/liquid plasma was finally elucidated.