铝阳极氧化多孔膜制备及Eu^(3+)组装

Preparation of Porous Anodic Aluminum Oxide Film and Eu^(3+) Assembly

在草酸体系中,采用二次阳极氧化法可制备大面积有序铝阳极氧化多孔膜(AAO),用X射线粉末衍射(XRD)仪进行物相分析,利用扫描电子显微镜(SEM)表征多孔膜的形貌。研究表明,低温条件下制备的多孔膜孔径大小分布均匀,有序性好。微孔在膜的表面沿二维空间规则排列,具有一定的六方对称准周期性,孔道相互平行且与铝基底垂直。低温条件下,草酸体系中电解获得的AAO膜以无定形结构存在,经过800℃高温退火后转化为γAl2O3。通过水热反应法,获得了Eu3+的铝阳极氧化多孔膜组装体(AAO∶Eu3+ ),研究了组装体系的光谱特性。结果表明,这种方法制备的发光材料具有非常高的组装浓度,其发光具有很高的色纯度。

In recent years, the synthesis of nanomaterials have received extremely interests of physicists, chemists and materialists in both fundamental and applied studies. As one of synthesis method of nanomate- rials, the synthesis by template is specially important, for example, more and more materials were produced by porous anodic aluminum oxide. In our recent work, wide range porous anodic aluminum oxide (AAO) film with highly ordered nanopore arrays was prepared by using a two-step anodization technique. The characterization of AAO template was achieved by scan electron microscope (SEM) and X-ray diffraction. In this work we made an attempt to introduce rare earth ion into AAO. Eu 3+ ion was introduced into the voids of porous anodic aluminum oxide film (AAO∶Eu 3+ ) by hydrothermal reaction, and the spectra of AAO∶Eu 3+ was discussed. The excitation spectra were measured by monitoring the 614 nm emission. There are three sets of lines can be observed: one strong broad band located at about 254 nm can be assigned to the O 2- →Eu 3+ charge transfer transition. Three weak sharp peaks located at around 363, 381 and 394 nm consisting of one set of peaks; while another single peak is located at 465 nm, these peaks are derived from 7D→ 5D absorbing transition of 4f electrons of Eu 3+ . Under 254 nm light excitation, the characteristic red emission peaks of Eu 3+ ions were observed. The peak at 614 nm is due to the 5D 0→ 7F 2 electric dipole transition of Eu 3+ , and its intensity is extremely stronger than that of the 5D 0→ 7F 1,3,4 transition, indicating that the Eu 3+ ions located in the host lattice have lower symmetry. The results showed that the materials synthesized by this method have favorable color purity and higher quenching concentration.