一步水热法合成兼具上转换发射增强和双模发射的NaYF_(4)∶Yb^(3+),RE^(3+)@CDs纳米复合材料  

One-Step Synthesis of NaYF_(4)∶Yb^(3+),RE^(3+)@CDs Nanocomposites with Enhanced Up-Conversion Emission and Dual-Mode Emission

作　　者：吴晓仪 康龙瑜 李蕊 盛昊阳 郑俊慧 邹林林 陈叶青[1] 禹庭 WU Xiaoyi;Kang Longyu;LI Rui;SHENG Haoyang;ZHENG Junhui;ZOU Linlin;CHEN Yeqing;YU Ting(School of Applied Physics and Materials,Wuyi University,Jiangmen 529020,China;School of Chemistry and Chemical Engineering,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]五邑大学应用物理与材料学院,广东江门529020 [2]西北师范大学化学化工学院,甘肃兰州730070

出　　处：《材料研究与应用》2024年第4期596-605,共10页Materials Research and Application

基　　金：金属复合增强荧光碳点的构建及活性氧的荧光检测应用研究项目(2019WGALH08)。

摘　　要：稀土离子(RE^(3+))掺杂上转换发射材料因具有优异的光学性能,在生物医学、离子检测、荧光传感和防伪等领域显示出巨大的应用潜力。碳点(CDs)作为一类新型的碳纳米材料,可以与稀土掺杂构建复合材料,通过将不同材料的优势结合,展现出纳米复合材料独特的性质和功能。然而,现有研究制备的复合材料均为大尺寸,限制了其多功能应用,纳米复合材料合成策略亟需进一步的研究和完善。将柠檬酸和尿素制备的CDs添加到NaYF_(4)∶Yb^(3+),RE^(3+)的前驱体溶液中,通过一步水热法制备了NaYF_(4)∶Yb^(3+),Er^(3+)@CDs纳米复合材料,采用XRD、TEM、FT-IR和XPS等表征手段深入研究了CDs对其结构和发射性能的影响。研究发现,CDs成功附着在NaYF_(4)∶Yb^(3+),RE^(3+)表面,NaYF_(4)∶Yb^(3+),RE^(3+)样品是具有立方相的单分散纳米球,CDs的引入未改变纳米复合材料中NaYF_(4)∶Yb^(3+),RE^(3+)的晶型。NaYF_(4)∶Yb^(3+),RE^(3+)@CDs纳米复合材料表现出优异的双模发射性能,分别归因于CDs的下转换发光和RE^(3+)掺杂离子的上转换特征发射。同时,CDs的引入使RE^(3+)上转换发射增强,其增强机制可能是:(1)通过CDs表面羧基与RE^(3+)的强配位,CDs成功钝化了NaYF_(4)部分表面缺陷;(2)利用CDs吸收激发电子,并将能量转移到RE^(3+)的较低能级,形成激发电子的富集。这种发光增强策略对于不同的掺杂离子(NaYF_(4)∶Yb^(3+),Er^(3+)、NaYF_(4)∶Yb^(3+),Tm^(3+)和NaYF_(4)∶Yb^(3+),Ho^(3+))也同样具有显著的增强效果。本研究结果为进一步改善RE^(3+)掺杂上转换发射材料的发光性能提供了一种简单且有效的新合成策略。Rare earth ions(RE^(3+))doped up-conversion luminescent materials have shown great potential for applications in biomedicine,fluorescence sensing,ion detection,and anti-counterfeiting due to their excellent optical properties.In this paper,we reported a facile synthetic strategy to synthesize NaYF_(4)∶Yb^(3+),RE^(3+)@CDs nanocomposites via hydrothermal synthesis by adding CDs prepared with citric acid and urea as precursors to a precursor solution of NaYF_(4)∶Yb^(3+),RE^(3+).The successful attachment of CDs on the surface of NaYF_(4)∶Yb^(3+),RE^(3+)was confirmed by XRD,TEM,FT-IR,XPS and other characterization methods.It was found that the as-prepared NaYF_(4)∶Yb^(3+),RE^(3+)were uniform monodisperse nanospheres,and the crystal form of NaYF_(4) in the nanocomposite is not altered by CDs.Under the excitation of UV light,the prepared NaYF_(4)∶Yb^(3+),RE^(3+)@CDs nanocomposites exhibit excellent dual-mode emission properties attributed to down-conversion emission of CDs and up-conversion characteristic emission of RE^(3+)-doped ions,respectively.Meanwhile,the addition of CDs has led to enhanced RE^(3+)up-conversion emission.It may be due to(1)the successful passivation of some surface defects of NaYF_(4) due to the strong coordination ability of the COOH on the surface of CDs with RE^(3+)ions;and(2)CDs are used to absorb excited electrons and transfer energy to the lower energy level of RE^(3+),resulting in the enrichment of the excitation electrons.This strategy is also effective for different doping ions(NaYF_(4)∶Yb^(3+),Er^(3+),NaYF_(4)∶Yb^(3+),Tm^(3+) and NaYF_(4)∶Yb^(3+),Ho^(3+)).The results of this study provide a simple and effective new synthesis strategy for further improving property of other RE^(3+)-doped up-conversion luminescent materials.

关 键 词：碳点 NaYF_(4) 下转换发光 上转换发射 纳米复合材料 双模发射 稀土发光 水热合成 

分 类 号：TB34[一般工业技术—材料科学与工程]