Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Normal University, Zhejiang 321004, China.
Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
Molecules. 2019 Jan 19;24(2):357. doi: 10.3390/molecules24020357.
In recent years, rare earth doped upconversion nanocrystals have been widely used in different fields owing to their unique merits. Although rare earth chlorides and trifluoroacetates are commonly used precursors for the synthesis of nanocrystals, they have certain disadvantages. For example, rare earth chlorides are expensive and rare earth trifluoroacetates produce toxic gases during the reaction. To overcome these drawbacks, we use the less expensive rare earth hydroxide as a precursor to synthesize β-NaYF₄ nanoparticles with multiform shapes and sizes. Small-sized nanocrystals (15 nm) can be obtained by precisely controlling the synthesis conditions. Compared with the previous methods, the current method is more facile and has lower cost. In addition, the defects of the nanocrystal surface are reduced through constructing core⁻shell structures, resulting in enhanced upconversion luminescence intensity.
近年来，由于具有独特的优点，稀土掺杂上转换纳米晶体在不同领域得到了广泛的应用。尽管稀土氯化物和三氟乙酸盐通常被用作纳米晶体合成的前体，但它们存在一定的缺点。例如，稀土氯化物价格昂贵，而稀土三氟乙酸盐在反应过程中会产生有毒气体。为了克服这些缺点，我们使用价格较低的稀土氢氧化物作为前体制备了具有多种形状和尺寸的β-NaYF₄纳米颗粒。通过精确控制合成条件，可以获得小尺寸的纳米晶体（15nm）。与以前的方法相比，目前的方法更加简便，成本更低。此外，通过构建核壳结构，减少了纳米晶体表面的缺陷，从而增强了上转换发光强度。
