Template synthesis of nanoparticle arrays of gold, platinum and palladium in mesoporous silica films and powders
Template synthesis of nanoparticle arrays of gold, platinum and palladium in mesoporous silica films and powders
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DOI：
10.1039/b311594a
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发表时间：
2004-02-21
影响因子：
--
通讯作者：
Ichikawa, M
中科院分区：
文献类型：
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作者：
Fukuoka, A;Araki, H;Ichikawa, M
采用浸涂法在玻璃板上制备了介孔氧化硅薄膜，并将其作为Au、Pt和Pd纳米粒子的载体。通过H-2-或光还原浸渍在膜上的金属前体，金属纳米颗粒形成有序的阵列结构的介孔中。通过用稀HF溶液溶解二氧化硅膜来分离纳米颗粒，并且用配体如1-十二烷硫醇和三苯基膦来稳定颗粒。分离的纳米颗粒的直径为2.5 nm，具有窄的分布，表明在介孔中形成均匀的颗粒。选择性地形成金属纳米颗粒而不是纳米线表明在2D-六方介孔二氧化硅膜中涉及3D-六方结构。为了研究3D六方结构的纳米颗粒的形成，将HMM-2粉末用作载体，并且实际上在HMM-2粉末中形成了Au和Pt纳米颗粒。XRD研究表明，膜/板中的Au纳米粒子在介孔孔道中具有各向异性取向。利用漫反射紫外-可见光谱，Au/膜/板样品在570-580 nm处产生一个弱的等离子体激元峰，与较大的Au颗粒相比，该峰向高波长移动了50-60 nm。
Mesoporous silica films were prepared on glass plates by a dip coating method, and the film/plate samples were used as a support for Au, Pt and Pd nanoparticles. By H-2- or photo-reduction of metal precursors impregnated on the films, metal nanoparticles are formed with an ordered array structure in the mesopores. The nanoparticles are isolated by dissolving the silica film with a dilute HF solution, and the particles are stabilized with ligands such as 1-dodecanethiol and triphenylphosphine. The diameter of the separated nanoparticles is 2.5 nm with narrow distributions, showing that uniform particles are formed in the mesopores. Selective formation of metal nanoparticles rather than nanowires suggests that a 3D-hexagonal structure is involved in the 2D-hexagonal mesoporous silica films. To study the formation of nanoparticles in a 3D-hexagonal structure, HMM-2 powder was used as a support, and in fact Au and Pt nanoparticles are formed in the HMM-2 powders. The XRD study suggests that the Au nanoparticles in the film/plate have an anisotropic orientation in the mesoporous channels. The Au/film/plate sample gives a weak plasmon peak at 570-580 nm using diffuse-reflectance UV-visible spectroscopy, which is shifted to high wavelength by 50-60 nm compared with larger Au particles.