Journal of Colloid and Interface Science, Vol.360, No.1, 93-99, 2011
Facile synthesis of 3D flowerlike CeO2 microspheres under mild condition with high catalytic performance for CO oxidation
Three-dimensional (3D) hierarchical flowerlike CeO2 microspheres with 5-8 mu m diameter were hydrothermally synthesized by using multiple surfactants at very mild condition (100 degrees C) and characterized by XRD, low-temperature N-2 adsorption, SEM, TEM, TG, FT-IR, and UV-vis spectroscopies. The results show that the flowerlike ceria prepared with the co-surfactant of sodium dodecyl sulfonic and PEG 600 possesses multilevel pore structure and low band gap energy. A possible formation mechanism of flowerlike ceria is that 3D flowerlike microspheres are assembled by 1D nanowires formed through an aggregation of OD nanoparticles. Based on the unique structure and morphology, the prepared flowerlike CeO2 exhibits more amount of surface capping oxygen, higher concentrations of CO3+ and O vacancy, and more (1 0 0) lattice planes, resulting in its higher catalytic activity for CO oxidation than general bulk ceria. Furthermore, photoluminescence property testing shows that flowerlike CeO2 exhibits the violet blue light emission with a blue shift, because of the quantum size effect, differing from general ceria. (C) 2011 Elsevier Inc. All rights reserved.
Keywords:Flowerlike CeO2 microspheres;Facile synthesis;Mild condition;Co-surfactant technology;Catalytic CO oxidation