二氧化铈纳米球的合成

摘要

使用尿素水热法合成了均匀的二氧化铈球型纳米材料. 纳米球是由纳米层以及纳米颗粒所构成的核壳结构,其平均粒径为320 nm, 同时表面主要暴露{111}晶面. 尿素水解所产生的氨气分子为纳米球状结构的形成提供了模板,而生成的碳酸根与氢氧根离子作为铈离子的沉淀剂. 使用氢气程序升温还原技术表征了氧化铈纳米球材料的氧化还原能力,同时以一氧化碳氧化为探针反应研究了其催化性能.%Ceria nanospheres with an average size of 320 nm were prepared by a urea-hydrothermal route. The ceria nanospheres had a core-shell structure constructed by nanoparticles and nanosheets that predominantly exposed the {111} planes. Urea hydrolysis produced CO2-3 and OH- species as precipitation agent and simultaneously produced ammonia bubbles that acted as a structure-directing agent for the formation of the CeO2 nanospheres. The redox properties and catalytic activity of the CeO2 nanospheres were examined by hydrogen temperature-programmed reduction and CO oxidation, respectively.