Effect of Ag content on the nanostructure and antimicrobial activity of CeO2.

Abstract

The morphological and antibacterial effects of CeO2 nanoparticles (NPs) with different amounts of Ag precursor were studied. The samples were synthesized with different percentages of silver nitrate content by co-precipitation method. The cerium nitrate hexahydrate was a precursor of Ce reagent, polyvinylpyrrolidone as dispersant agent, and ammonium hydroxide as a precipitating agent. The obtained particles were annealed at 400°C and characterized by X-ray diffraction, scanning electron microscope (SEM), transmission electron microscopy (TEM), and N2 physisorption. The particles show high crystallinity, whose size decreases slightly by the effect of Ag precursor incorporation. These particle morphologies studied by SEM and TEM revealed the spherical shape of CeO2 NPs. Furthermore, the Ag particles were observed with a size of around 30nm. Selected area electron diffraction patterns confirm the cubic structure of CeO2, also the cubic structure of Ag particles. Besides, it was determined that Ag incorporation has no significant influence on the textural properties of NPs. In addition, the antibacterial activity was evaluated against gram-negative and gram-positive microorganisms. The quantitative results showed that the antimicrobial activity increased depending on the Ag amount incorporated, reaching up to 99.999% of the growing reduction rate.