Urea and surfactant assisted hydrothermal growth of ceria nanoparticles
Urea and surfactant assisted hydrothermal growth of ceria nanoparticles
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DOI：
10.1016/j.colsurfa.2020.124944
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发表时间：
2020-09-20
影响因子：
5.2
通讯作者：
Som, Sudipta
中科院分区：
文献类型：
--
作者：
Chavhan, Madhav P.;Lu, Chung-Hsin;Som, Sudipta
通过改进的水热方法制备氧化铈纳米粒子，以减少传统水热路线中的反应持续时间。尿素和NaOH一起使用可以在短时间内快速生长二氧化铈纳米立方体。在尿素的帮助下形成Ce-O-Ce键以生长CeO2核，并且在基础介质中的各向异性生长导致纳米立方体形貌的形成。在前体溶液中进一步添加十六烷基三甲基溴化铵（CTAB）作为封端剂和结构导向剂，引导二氧化铈纳米结构从球形生长到不规则的多边形形态。水热反应后形成具有高反应性（1 0 0）面的18-20 nm尺寸的二氧化铈纳米立方体。另一方面，CTA(+)组将颗粒尺寸减小至8-10 nm，并暴露出(1 1 1)稳定面。此外，在表面活性剂的帮助下获得的二氧化铈纳米结构在立方萤石结构中表现出固有的氧空位和较高的Ce3+浓度。此外，带隙和乌尔巴赫能量计算表明结构无序的增加和二氧化铈形态缺陷的贡献顺序为：纳米立方体<纳米板<多边形纳米结构<纳米球。目前的研究表明了一种在短反应时间内合成二氧化铈纳米粒子的新方法。
Cerium oxide nanoparticles were prepared via a modified hydrothermal approach to reduce the reaction durations in the conventional hydrothermal route. Urea and NaOH were used together for the fast growth of ceria nanocubes within a short reaction period. The formation of Ce-O-Ce bonds to grow CeO2 nuclei with the help of urea, and the anisotropic growth in the base medium led to the formation of nanocube morphology. Cetyltrimethylammonium bromide (CTAB) was added further in the precursor solution as a capping and structure directing agent that directed the growth of ceria nanostructures from spherical to irregular polygonal morphology. Ceria nanocubes of 18-20 nm sizes with highly reactive (1 0 0) faces were formed after hydrothermal reaction. On the other hand, CTA(+) group reduced the particle sizes to 8-10 nm with the (1 1 1) exposed stable faces. In addition, ceria nanostructures obtained with the assistance of surfactants show intrinsic oxygen vacancies and enhanced concentrations of Ce3+ in cubic fluorite structure. Furthermore, band gap and Urbach energy calculations show that the increase in structural disorder and contribution of the defects in ceria morphologies of the order: nanocubes < nanoplates < polygonal nanostructures < nanospheres. The present research indicated a novel approach to synthesize ceria nanoparticles within short reaction durations.