介孔SiO2负载和包覆的纳米金属颗粒的制备与研究

制备了以SiO2为核、介孔SiO2为壳的核-壳颗粒负载纳米金属颗粒以及介孔SiO2壳层包覆SiO2负载的纳米金属颗粒。结果表明,十六烷基三甲基溴化胺(CTAB)作为模板剂,有助于介孔SiO2壳层包覆SiO2核的结构形成,介孔SiO2壳层的孔径方向垂直于SiO2核的表面;在聚乙烯吡咯烷酮(PVP)的稳定作用下,Pt纳米颗粒能均匀地分布在介孔SiO2壳层的表面。单分散SiO2颗粒经过3-氨丙基三乙氧基硅烷(APS)功能化后,可负载纳米金属颗粒。进一步研究表明,以SiO2负载纳米金属颗粒为核,NH3.H2O,乙醇和水为分散剂,CTAB为模板剂,正硅酸乙酯(TEOS)为硅源,还能制备介孔SiO2壳包覆SiO2负载的纳米金属颗粒,而且介孔SiO2壳层的厚度可通过TEOS的含量调节。

Preparation and Characterization of Mesoporous Silica-Supported and Encapsulated Nano-Metal Particles

Metal nanoparticles supported on the core-shell particles with SiO2 as core and mesoporous SiO2 as shell and mesoporous SiO2-encapsulated metal nano particles supported on SiO2 particles were prepared in this work.The results showed that SiO2 particles as cores could be coated by mesoporous SiO2 shell with aid of CTAB template and the direction of mesoporous channels was perpendicular to the surface of SiO2 core.Pt nanoparticles could be homogeneously supported on the surface of mesoporous SiO2 shell with aid of PVP.SiO2 particles functionalized with APS could support metal nanoparticles.The further study indicated that the mesoporous SiO2-encapsulated metal nanoparticles supported on SiO2 particles could be prepared with SiO2 particles-supported metal nanoparticles as cores,NH3·H2O,ethanol and water as dispersant,CTAB as template and TEOS silica precursor.It was also found that the thickness of mesoporous SiO2 shell could be controlled by the content of TEOS.