层状稀土氢氧化物的合成、剥离、表面修饰及其荧光检测研究
发布时间：2019-06-22 18:30
【摘要】：作为层状主客体化合物的新成员,层状稀土氢氧化物(LREHs)结合了具有丰富物理化学性质的稀土元素和广泛可调性的客体阴离子。这类化合物已经吸引了大量的研究关注,而且在光学、催化、生物医药等各个领域存在潜在的应用价值。本文介绍了层状稀土氢氧化物的合成、结构表征、剥离及其对有机芳香化合物的荧光检测研究。我们分别合成了铈、钐、铕、铽、镝五种稀土元素的层状氢氧化物,并且通过对它们进行元素分析、X射线能谱(EDX)及稀土滴定等表征确定了它们的组成式,如下:1:Ce_2(OH)_4.1(SO_4)0.9·2.3H_2O2:Sm(OH)_(2.6)Cl_(0.4)·1.8H_203:Eu(OH)_(2.6)Cl_(0.4).1.4H_204:Tb(OH)_(2.6)Cl_(0.4)·1.OH_205:Dy(OH)_(2.5)Cl_(0.5)·0.5H_20通过TEM和SEM表征,进一步证明合成了层状稀土氢氧化物,并且清晰的观察到它们的形貌。层状氢氧化铕(LEuH)形状接近长方体形,尺寸较大且大小均匀,长约为106-207nm,宽约为52-167nm,厚度约为23.6nm。层状氢氧化铈呈片状,形状为菱形,其大小尺寸不一,棱长大在96.6nm-1.0μm,厚约11.5nm。层状氢氧化铽呈片状,形状尺寸不均一,形状接近正方形,尺寸范围在222-606nm,片较厚,厚度约为54.4nm。层状氢氧化钐尺寸较大,大约(2.5)μm,且较薄,大约4-5nm厚,多处有折叠现象;层状氢氧化镝形貌较好,大小居中,为180nm左右,厚度较薄,为20nm左右,而且呈花状结构,形貌独特。荧光测定表明,合成的层状氢氧化物具有明显的稀土元素特征峰,且发光强度较强。为了进一步研究氢氧化铕的性质,我们又通过不同方法对其进行了剥离实验,并且通过TEM、SEM和XRD等表征证明其被剥离完全,最后测剥离后的荧光性质,发现完全剥离后,其荧光强度增强。然后我们又用对苯二甲酸(P-PTA)对LEuH进行了表面修饰,通过调控反应温度、对苯二甲酸和LEuH的摩尔比来观察其荧光强度的变化趋势,发现随着对苯二甲酸修饰量的增加,LEuH的荧光强度逐渐增强。通过元素分析、差热-热重分析(DTA-TG)、红外光谱分析证实对苯二甲酸成功地修饰到了 LEuH表面。且TEM表明,LEuH的形状大小保持良好没有损坏。三价稀土离子通常能为客体分子提供路易斯酸性位点,增强主客体之间的相互作用,可以作为很好的荧光检测材料。因此,我们用LEuH来检测p-PTA、2,6-吡啶二羧酸(DPA)等有机芳香化合物。p-PTA羧酸根的氧原子会与LEuH表面的Eu~(3+)发生配位,从而增大LEuH的荧光强度。理论上,DPA羧酸根的氧原子也会与Eu~(3+)发生配位,从而增强LEuH的荧光强度。但实验结果表明,LEuH能够用来检测p-PTA,但尚不能对DPA进行检测。
[Abstract]:As a new member of layered host-guest compounds, layered rare earth hydroxide (LREHs) combines rare earth elements with rich physical and chemical properties and widely adjustable guest anions. These compounds have attracted a lot of research attention, and have potential application value in optics, catalysis, biomedicine and other fields. In this paper, the synthesis, structure characterization, stripping and fluorescence detection of layered rare earth hydroxide are introduced. The layered hydroxide of cerium, samarium, europium, terbium and dysprosium were synthesized and their composition was determined by elemental analysis, X-ray energy dispersive spectroscopy (EDX) and rare earth titration. As follows: 1:Ce_2 (OH) _ 4.1 (SO_4) 0.9. 2.3H _ 2O2:Sm (OH) _ (2.6) Cl_ (0.4) 1.8H_203:Eu (OH) _ (2.6) Cl_ (0.4). 1.4H_204:Tb (OH) _ (2.6) Cl_ (0.4) 1.OH_205:Dy (OH) _ (2.5) Cl_ (0.5) 0.5H_20 was characterized by TEM and SEM. It is further proved that layered rare earth hydroxide has been synthesized and their morphology has been clearly observed. The shape of layered europium hydroxide (LEuH) is close to the cuboid shape, the size is large and uniform, the length is about 106 nm, the width is about 52 鈮，
本文编号：2504850
[Abstract]:As a new member of layered host-guest compounds, layered rare earth hydroxide (LREHs) combines rare earth elements with rich physical and chemical properties and widely adjustable guest anions. These compounds have attracted a lot of research attention, and have potential application value in optics, catalysis, biomedicine and other fields. In this paper, the synthesis, structure characterization, stripping and fluorescence detection of layered rare earth hydroxide are introduced. The layered hydroxide of cerium, samarium, europium, terbium and dysprosium were synthesized and their composition was determined by elemental analysis, X-ray energy dispersive spectroscopy (EDX) and rare earth titration. As follows: 1:Ce_2 (OH) _ 4.1 (SO_4) 0.9. 2.3H _ 2O2:Sm (OH) _ (2.6) Cl_ (0.4) 1.8H_203:Eu (OH) _ (2.6) Cl_ (0.4). 1.4H_204:Tb (OH) _ (2.6) Cl_ (0.4) 1.OH_205:Dy (OH) _ (2.5) Cl_ (0.5) 0.5H_20 was characterized by TEM and SEM. It is further proved that layered rare earth hydroxide has been synthesized and their morphology has been clearly observed. The shape of layered europium hydroxide (LEuH) is close to the cuboid shape, the size is large and uniform, the length is about 106 nm, the width is about 52 鈮，
本文编号：2504850
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