基于分子筛模板的银/硅铝无定形结构复合材料的合成及光谱性质

利用硅铝无定形结构作为保护层的银纳米颗粒在杀菌和催化领域具有重要应用. 银纳米颗粒的形貌控制是其优异性能的重要保证, 尤其是具有规则结构的银纳米颗粒的合成一直是该领域的难点. 本文以亚稳态结构的硅铝分子筛作为模板, 在室温条件下采用离子交换方法, 通过调整银离子的含量和离子交换时间, 控制银在分子筛中的分布和含量, 在还原剂N(C₂H₅)₃存在下, 通过微波还原反应获得了不同银/硅铝无定形结构比例的复合材料. 透射电子显微镜测试结果表明， 不同比例的前驱体经微波法还原后, 小尺寸的银纳米颗粒可以分布在无定形的硅铝基质中; 当增大银的比例后, 银纳米颗粒则出现项链式结构, 并且由无定形硅铝薄层链接并包裹. 这类结构既具有银纳米颗粒的催化性能, 同时又在硅铝薄层的保护下表现出良好的稳定性, 在杀菌和催化领域具有广泛的应用前景.

Synthesis and Spectral Properties of Ag/SiO2-Al2O3 Composite Nanomaterial Based on Molecular Sieve Template

Ag nanoparticles with SiO₂-Al₂O₃ amorphous structure as the protective layer have important applications in the field of sterilization and catalysis. The morphology control of Ag nanoparticles is a privotal guarantee for its excellent performance， especially the synthesis of Ag nanoparticles with regular structures has always been a difficulty in this field. In this paper， the metastable structure of SiO₂-Al₂O₃ molecular sieve was used as the template， and the ion exchange method is adopted at room temperature. The ion exchange time was adjusted to control the distribution and content of Ag in the molecular sieve. In the presence of reducing agent N（C₂H₅）₃， amorphous composite structure materials with different ratios of Ag/SiO₂-Al₂O₃ were obtained by microwave reduction reaction. The reslults of transmission electron microscopy showed that small-sized Ag nanoparticles can be distributed in the amorphous SiO₂-Al₂O₃ matrix after different proportions of precursors were reduced by microwave method. The Ag nanoparticles showed necklace-like structure and were linked and wrapped by an amorphous SiO₂-Al₂O₃ lamella when the proportion of silver was increased. This type of structure not only has the catalytic performance of Ag nanoparticles， but also shows good stability under the protection of the SiO₂-Al₂O₃ lamella. It has a wide range of application prospects in the sterilization and catalysis fields.