Yan Ruoxue, Sun Xiaoming, Wang Xun, Peng Qing, Li Yadong
Department of Chemistry and Key Laboratory of Atomic and Molecular Nanosciences (National Center for Nanoscience and Nanotechnology, Ministry of Education, China), Tsinghua University, Beijing 100084, P. R. China.
Chemistry. 2005 Mar 18;11(7):2183-95. doi: 10.1002/chem.200400649.
The fundamental understanding of the relationship between crystal structure and the dynamic processes of anisotropic growth on the nanoscale, and exploration of the key factors governing the evolution of physical properties in functional nanomaterials, have become two of the most urgent and challenging issues in the fabrication and exploitation of functional nanomaterials with designed properties and the development of nanoscale devices. Herein, we show how structural and kinetic factors govern the tendency for anisotropic growth of such materials under hydrothermal conditions, and how the crystal structure and morphology influence the optical properties of Ln3+-doped nanocrystals. The synthesis of phase-pure and single-crystalline monoclinic, hexagonal, and tetragonal one-dimensional LnPO4 nanostructures of different aspect ratios by means of kinetically controlled hydrothermal growth processes is demonstrated. It is shown that the tendency for anisotropic growth under hydrothermal conditions can be enhanced simply by modifying the chemical potentials of species in the reaction solution through the use of carefully selected chelating ligands. A systematic study of the photoluminescence of various Eu3+-doped lanthanide phosphates has revealed that the optical properties of these nanophosphors are strongly dependent on their crystal structures and morphologies.
对晶体结构与纳米尺度各向异性生长动力学过程之间关系的基本理解，以及对功能纳米材料物理性质演变的关键因素的探索，已成为制备和开发具有设计性能的功能纳米材料以及发展纳米级器件过程中最紧迫且最具挑战性的两个问题。在此，我们展示了结构和动力学因素如何在水热条件下控制此类材料的各向异性生长趋势，以及晶体结构和形态如何影响掺杂Ln3+的纳米晶体的光学性质。通过动力学控制的水热生长过程，展示了如何合成具有不同纵横比的纯相、单晶单斜、六方和四方一维LnPO4纳米结构。结果表明，通过使用精心选择的螯合配体来改变反应溶液中物种的化学势，可简单地增强水热条件下的各向异性生长趋势。对各种Eu3+掺杂镧系磷酸盐的光致发光进行的系统研究表明，这些纳米磷光体的光学性质强烈依赖于它们的晶体结构和形态。
