Nanocrystalline CeO2 particles were firstly prepared by two-stage non-isothermal precipitation, i.e. precipitating at 70 °C and aging at another temperature. Experimental results showed that the intermediates at the end of precipitation stage were needle-like mixtures of Ce 3+-Ce4+ compounds. The subsequent aging temperature played an important role on the shape and size of final products. As the aging temperature suddenly reduced to 0 °C, the resultant particles retained their original needle-like structure via the topotactic mechanism, which cannot be obtained by isothermal precipitation. As raising the aging temperature above 50 °C, the products were hexagonal and grown up with increasing temperature via the dissolution-recrystallization mechanism. Moreover, all products were cubic-fluorite structured CeO2 with negligible Ce3+ content. As compared to the nanohexagons (aged at 90 °C), the nanoneedles (aged at 0 °C) exhibited an unordinary red shift in the UV absorption and possessed a smaller bandgap energy. © 2004 Elsevier Ltd. All rights reserved.
CITATION STYLE
Chen, H. I., & Chang, H. Y. (2005). Synthesis and characterization of nanocrystalline cerium oxide powders by two-stage non-isothermal precipitation. Solid State Communications, 133(9), 593–598. https://doi.org/10.1016/j.ssc.2004.12.020
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