Controllable synthesis, characterization, and CO oxidation activity of CeO2 nanostructures with various morphologies

CeO2 nanostructures with various morphologies were prepared through controlling preparation conditions via a hydrothermal method without any surfactants and templates. Cerium acetate, cerium chloride and cerium nitrate were used as cerium precursors to investigate the influence of anions on the growth process of CeO2 nanostructures. The morphology evolution of CeO2 and Ce(OH)3 nanostructures indicates that the anions play an important role for the growth kinetics of resulting samples. Cl− and Ac− ions promoted the formation of one dementional (1D) CeO2 nanostructures such as nanowires, nanorods and nano hexagonal prisms, while the oxidizing anion NO3- facilitated the synthesis of CeO2 nanocubes. The hydrothermal reaction temperature is another key to govern the morphologies of CeO2 nanostructures. The formation process of the nanostructures was explored and the possible growth mechanism was discussed. The variety of CeO2 nanostructures represented inequable catalytic performance for CO oxidation. Because of different surface areas and structures, CeO2 nanowires revealed the best catalysis performance while that of the nanocubes is the worst.