摘要
采用共沉淀法水热合成了稀土Eu掺杂的镁铝类水滑石层状化合物（MgAlEuCO3-HTIcs）。探讨了溶液pH值、组分配比、陈化时间和温度对水滑石晶体结构的影响。利用XRD、FT-IR和荧光光谱对样品的组成和性质进行表征。XRD、FT-IR结果表明：当n（M^2＋）：n（M^3＋）=3，n（Eu^3＋）：[n（Al^3＋）＋n（Eu^3＋）]=5％-50％。pH=10±0．1条件下进行多种离子共沉淀，并经100℃、12h水热处理后均可得到结晶好、纯度高的镁铝铕类水滑石；MgAlEuCO3-HTlcs保持了水滑石的层状结构，在600-900cm^-1、I250—1350cm^-1和3420—3480cm^-1有红外吸收；荧光光谱测试发现掺杂稀土Eu^3＋离子的MgAlEuCO3-HTlcs具有Eu^3＋的^5D0→^7FJ特征光谱。稀土Eu^3＋成功地插层组装进入HTlcs层板，MgAlEuCO3-HTlcs化合物是一种具有选择性红外吸收和红色发光性质的双功能材料。
Hydrotalcite-like compounds （HTlcs）, which are formulated as [M1-x^2＋ Mx^3＋（OH）2]An/s^n-·MH2Ohave received increase interest owing to their particular properties such as infrared absorption. The properties are derived from their special layers structure, which are made of metal cations （M^2 ＋ and M^3 ＋ ） of similar ionic radii and coordinated by six oxygen atoms forming M^2＋ /M^3＋ （OH）6 octahedra. Luminescent materials containing rare-earth ions have been special interest for their sharp and intense emission bands based on f→f transitions of rare-earth ions. In fact, europium compounds are the most widely used due to their efficient red-emitting luminescence, so doping of europium ions into HTlcs makes it possible to combine the optical properties of molecular compounds with the mechanical and chemical stability of a solid matrix. Therefore, it suggests that there is a new method of designing dual-functional materials.
In order to getting dual-functional materials with red luminescence and selectivity IR adsorption properties, we studied the HTlcs compound containing Eu^3＋ ions. The samples of Mg-Al-Eu-hydrotalcite-like compounds （MgAlEuCO3-HTIcs） were prepared by co-precipitation and through hydrothermal treatment. Results of XRD showed that the pure MgAlEuCO3-HTlcs were obtained from solution of magnesium, aluminium and europium nitrates, n（ Mg^2＋ ） ： n（ Al^3＋ ） = 3, n（ Eu^3 ＋ ） ： [ n（ Al^3＋ ） ＋ n（ Eu^3 ＋ ） ] = 5% - 50%, by co-precipitation with a mixture of sodium carbonate and hydroxide at a fixed pH value of 10 ± 0.1, and hydrothermal treating at 100 ℃ for 8 h. The MgAlEuCO3-HTlcs crystallinity decreases with increasing Eu^3＋ dosage in the synthesis mixture, and the value of dllo of MgAlEuCO3-HTlcs is more larger in XRD at one time. Three intense IR bands of FF-IR spectra at 600 - 900 cm^- 1,1 250 - 1 350 cm ^- 1 and 3 420 - 3 480 cm ^- 1 are argument with MOH （M = Mg, Al, Eu）, CO3 and OH stretching vibrations, respectively. Under excitation by 399 nm, there are three sharp emissions peaked at 594,620 and 700 nm in emission spectrum of MgAlEuCO3-HTIcs, which belong to the ^5 Do→^7 Fj （ J = 1,2,4） transition of Eu^3 ＋ ion. Besides, the intensity of 1 changed with the increasing of Eu/Al molar ratio. All of results revealed that a few Al^3＋ ions in layers of HTlcs were replaced by Eu^3＋ ions in our samples.
It was found that the MgAlEuCO3-HTIcs compound is a novel dual-function material with selectivity absorbing infrared wavelength and red luminescence.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2007年第1期67-73,共7页
Chinese Journal of Luminescence
基金
国家自然科学基金资助项目(20371017)
关键词
铕
类水滑石
红外吸收
发光
europium
hydrotalcite-like compounds
IR absorption
luminescence
