Synthesis and Characterization of the Properties of Ceria Nanoparticles with Tunable Particle Size for the Decomposition of Chlorinated Pesticides

Featured Application Contamination of soil and water by halogenated hydrocarbons and other organic chemicals has become a serious issue. Organic chemicals are likely to exert acute lethal and chronic effects on sensitive fish, invertebrate or algae species. Organic chemicals endanger the health of freshwater ecosystems on the continental scale worldwide. These frightening problems need to be quickly and efficiently solved in order to restore balance in ecosystems. Ceria-based nanoobjects (e.g., nanoparticles, nanowires, nanosheets) have enormous potential to be used as catalysts for the decomposition of halogenated hydrocarbons. Ceria nanoobjects will be used in the future for the improvement of environmental conditions wherever the water or soil is contaminated by halogenated pesticides. Ceria nanoparticles are well known for their catalytic properties, which are commonly used in the automotive industry and other chemical branches. In this contribution, ceria nanoparticles were prepared by a simple precipitation reaction of cerium (IV) sulfate and ammonia. Such nanoparticles were very fine, with an approximate crystallite size of 2 nm. Crystallite sizes of these nanoparticles were adjusted by controlled heating, showing different catalytic properties. After thermal treatment, the surface area and crystallite size of nanoparticles were also compared by means of XRD and a sorption analyzer utilizing Brunauer-Emmet-Teller (BET). Morphology was studied by SEM, high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED). Thin layers of ceria nanoparticles on silica glass and alumina ceramic underlays were also prepared and studied by SEM and EDS to demonstrate the possibility of ceria immobilization using thermal treatment of raw nanoparticles. The catalytic activity of the nanoparticles was tested on a 2,4,6-trichlorophenol aqueous solution and compared by UV-VIS spectroscopy.