Multi-analytical approach of the influence of sulphate ion on the formation of cerium(III) fluoride nanoparticles in precipitation reaction

Cerium(III) fluoride (CeF3) nanoparticles were produced in aqueous solution by precipitation using cerium(III) excess and sulphate ions in order to assist the aggregation. This process was studied by dynamic light scattering in the solution. The nanonparticles (NPs) were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX). The CeF3 NPs have cylindrical shape and domain size of 8.1 nm estimated from the XRD analysis. The EDX spectrum shows sulphur content of the NPs, which indicates the sulphate adsorption on their surface. The spectrophotometric study confirms only an outer-sphere complex existing between the cerium fluoro species and the sulphate ion. Infrared (IR) and Raman spectroscopy was used in order to characterize the structure of the complex on the surface of the NPs. It can be concluded that also cerium hydroxo species adsorbed on the surface from the solution and formed a chelate complex with the sulphate ions.