TY - GEN
T1 - Shape-controlled formation of ceria nanocrystals in a surfactant- And template-free process
AU - Wang, Wei
AU - Gu, Baohua
AU - Doktycz, Mitchel J.
PY - 2009
Y1 - 2009
N2 - Ceria (CeO2) nanoparticles are widely used for applications in catalysis, fuel cells, and microelectronics. An important factor that influences the catalytic performance of ceria is the shape of nanocrystals. Here we present a facile two-step procedure to synthesize ceria nanocrystals with controlled shapes in a surfactant- and template-free system. Cerium hydroxide precursor was first prepared via a chemical precipitation, and ceria was obtained by subsequent hydrothermal treatment. The as-synthesized nanocrystals were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Spherical and cubic nanoparticles with different sizes and two-dimensional nanorods/nanowires with different aspect ratios were obtained by manipulating the experimental conditions. Studies on the formation mechanism indicate that counter anions in solution played crucial roles in tuning the shape of the nanocrystals. The reaction time and temperature are also important factors influencing the structural evolution of the nanocrystals. The formation of ceria nanowires appears to result from the aggregation and orientation growth of smaller-size ceria nanocrystals. These nanocrystals exhibit strong UV absorption properties for catalytic applications, and the methodology is simple and inexpensive and has great potential for scale-up applications.
AB - Ceria (CeO2) nanoparticles are widely used for applications in catalysis, fuel cells, and microelectronics. An important factor that influences the catalytic performance of ceria is the shape of nanocrystals. Here we present a facile two-step procedure to synthesize ceria nanocrystals with controlled shapes in a surfactant- and template-free system. Cerium hydroxide precursor was first prepared via a chemical precipitation, and ceria was obtained by subsequent hydrothermal treatment. The as-synthesized nanocrystals were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Spherical and cubic nanoparticles with different sizes and two-dimensional nanorods/nanowires with different aspect ratios were obtained by manipulating the experimental conditions. Studies on the formation mechanism indicate that counter anions in solution played crucial roles in tuning the shape of the nanocrystals. The reaction time and temperature are also important factors influencing the structural evolution of the nanocrystals. The formation of ceria nanowires appears to result from the aggregation and orientation growth of smaller-size ceria nanocrystals. These nanocrystals exhibit strong UV absorption properties for catalytic applications, and the methodology is simple and inexpensive and has great potential for scale-up applications.
UR - http://www.scopus.com/inward/record.url?scp=78649801956&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:78649801956
SN - 9780841200050
T3 - ACS National Meeting Book of Abstracts
BT - American Chemical Society - 238th National Meeting and Exposition, ACS 2009, Abstracts of Scientific Papers
T2 - 238th National Meeting and Exposition of the American Chemical Society, ACS 2009
Y2 - 16 August 2009 through 20 August 2009
ER -