Synthesis of CeO2 nanocrystals via a dissolution-based hydrothermal process

• Main Authors: Mei-Tsan Kuo, 郭美贊
• Other Authors: Chung-Hsin Lu
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/yrd928

碩士 === 國立臺灣大學 === 化學工程學研究所 === 107 === A modified hydrothermal route was successfully developed to synthesize cerium oxide (CeO2) nanocrystals with high crystallinity. Cerium carbonate hydroxide (CeOHCO3) and hydrogen peroxide (H2O2) were used as the source of cerium ions and oxidizer, respectively, and CeO2 nanocrystals with crystallite size of more than 30 nm were successfully synthesized at 180 °C within 6 h. Ce3+ ions are released from CeOHCO3 particles under hydrothermal condition, and forming CeO2 via the following oxidization-hydrolysis-dehydration process. The slow dissolution of CeOHCO3 particles controls the releasing rate of cerium ions, which can control the formation nuclei and would be benign to grow CeO2 nanocrystals with large crystallite size. The growth mechanism of the CeO2 nanocrystals is elucidated as an autocatalytic dissolution-oxidization-crystallization process, and protons are proved to have catalytic effects. The present protocol can significantly reduce the reaction time and the reaction temperature for synthesizing CeO2 nanocrystals with high crystallinity, and could potentially be applied to synthesize other oxide materials.