Synthesis And Characterization Of Nanometer Scale Ceria, Lanthana And Their Complexes

With the development of scientific research, ceria and lanthana in nanometer scale have recently attracted a lot of research interest due to their unique properties and wide range of applications. A wide range of techniques has been developed for the synthesis of ceria and lanthana, including thermal hydrolysis, high-energy ball milling, sol-gel, precipitation, microwave irradiation, semi-batch reactor, and combustion. However, the most of these techniques are spend time due to multi-step syntheses or ageing, consume intensively energy, and being unfriendly for environment. In addition, when the particles with extremely small sizes are desired, the complexity, and sometimes the cost of manufacture, increases further. Here, we report preparation of the nanometer-scale rare earth oxide particles via an easy thermo-decomposition method of complexes. The complexes are derived from the reaction of rare earth nitrate with o-nitro-benzoic acid. The characterization of the complexes and ceria, lanthana powders are presented, respectively.(1) Nanometer-scale CeO2 particles (3-20 nm) have been synthesized by the thermo-decomposition of a new Ce3+ complex taking o-nitro-benzoic acid as ligand. Structure and properties of the Ce3+complexes have been confirmed by XRD, FT-IR and TGA. And the CeO2 powders have been characterized by Raman, XRD, TEM, AFM and BET. The CeO2 powders exhibit a specific surface area of ~74.86 m~2 g~-1. Control over the particle size, surface area, yield, and state of agglomeration could be achieved through variation of the experimental conditions.The nanometer-scale La2O3 particles (15-40 nm) have been synthesized by the thermo-decomposition of a new La3+ complex taking o-nitro-benzoic acid as ligand. Structure and properties of the La3+complexes have been confirmed by XRD, FT-IR and TGA. The La2O3 powders have been characterized by XRD and TEM. And the result of the XRD indicates that some nanometer La2O3 powders can reacted with CO2 in air.(2) {Ce[o-C6H4(NO2)(COO)]3-2DMF}2 and {La[o-C6H4(NO2)(COO)]3-2DMF}2 are synthesized, and the structure of the complex is characterized by FT-IR, ~1H NMR, ~13C NMR, UV, fluorescent emission spectra and X-ray single-crystal diffraction analysis.