Ceria-Catalyzed Hydrolytic Cleavage of Sulfonamides.

Nanoceria is a promising nanomaterial for the catalytic hydrolysis of a wide variety of substances. In this study, it was experimentally demonstrated for the first time that CeO nanostructures show extraordinary reactivity toward sulfonamide drugs (sulfadimethoxine, sulfamerazine, and sulfapyridine) in aqueous solution without any illumination, activation, or pH adjustment. Hydrolytic cleavage of various bonds, including S-N, C-N, and C-S, was proposed as the main reaction mechanism and was indicated by the formation of various reaction products, namely, sulfanilic acid, sulfanilamide, and aniline, which were identified by HPLC-DAD, LC-MS/MS, and NMR spectroscopy.

Effect of Surface Treatment of Nanocrystalline CeO on Its Dephosphorylation Activity and Adsorption of Inorganic Phosphates.

The surface of nanocrystalline cerium oxide (CeO) was treated with various chemical agents by a simple postmodification method at 25 °C and atmospheric pressure. Hydrogen peroxide, ammonium persulfate, deionized water, ascorbic acid, and ortho-phosphoric acid were used in order to study and evaluate their effect on surface materials, such as surface area, crystallite size, number of surface hydroxyl groups, particle morphology, and Ce/Ce ratio. Paraoxon-methyl (PO) decomposition and inorganic phosphate adsorption were used to evaluate the effect of surface treatment on catalytic and adsorption properties.

Cerium-Bismuth Oxides/Oxynitrates with Low Toxicity for the Removal and Degradation of Organophosphates and Bisphenols.

Nanoscale cerium-bismuth oxides/oxynitrates were prepared by a scalable low-temperature method at ambient pressure using water as the sole solvent. Solid solutions were formed up to a 1:1 Ce/Bi molar ratio, while at higher doping levels, bismuth oxynitrate photocatalysts with a pronounced layered structure were formed. Bismuth caused significant changes in the structure and surface properties of nanoceria, such as the formation of defects, oxygen-containing surface groups, and Lewis and Brønsted acid sites.

Synthesis and characterization of TiO/Mg(OH) composites for catalytic degradation of CWA surrogates.

Surface catalyzed reactions can be a convenient way to deactivate toxic chemical warfare agents (CWAs) and remove them from the contaminated environment. In this study, pure titanium oxide, magnesium hydroxide, and their composites TiO/Mg(OH) were prepared by thermal decomposition and precipitation of the titanium peroxo-complex and/or magnesium nitrate in an aqueous solution. The as-prepared composites were examined by XRD, XPS, HRTEM, and nitrogen physisorption.

Mesoporous cerium oxide for fast degradation of aryl organophosphate flame retardant triphenyl phosphate.

Cerium oxide nanoparticles were prepared by calcination of basic cerous carbonate (as a precursor) obtained by precipitation from an aqueous solution. Prepared samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM), BET (Brunauer-Emmett-Teller) surface area and porosity measurement. Prepared cerium oxide was applied as a destructive sorbent for the fast and safe degradation of organophosphorus flame retardant triphenyl phosphate (TPP).