介孔SiO2纳米棒的制备及其表面锚接金纳米粒子

 以正硅酸乙酯为硅源，十六烷基三甲基溴化铵为模板剂，聚乙二醇为分散剂，采用溶胶-凝胶法制备出SiO₂纳米粒子，应用透射电镜、扫描电镜、X射线衍射仪、红外光谱仪和X射线能谱仪研究了粒子的性能。结果表明：所得产物是具有周期性规则介孔的棒状粒子，长径比随着硅源、模板剂和分散剂浓度的降低而减小；向反应体系中引入乙醇，随着乙醇与水的体积比例的增加，粒子由棒状向球状转变，进而形成不规则絮状凝聚体。用硅烷化技术对SiO₂纳米棒表面进行修饰后吸附平均粒径3.7 nm的金种子，再用多轮生长法使种子长大，经过30轮生长，种子平均粒径增大至59 nm，得到了SiO₂-Au复合纳米体系。透射电镜和紫外-可见分光光度计分析结果表明：金纳米粒子锚接在SiO₂纳米棒表面的某些点位，呈分散分布；复合体系表现出强烈的金的表面等离子体共振吸收峰，该峰随着金粒子的粒径增大，在500~700 nm波段内红移。

Preparation of mesoporous SiO2 nanorods and anchoring of Au nanoparticles on their surface

SiO2 nanoparticles were prepared by sol-gel method with tetraethyl-ortho-silicate(TEOS) as silica source, cetyltrimethylanmmonium bromide(CTAB) as template, and polyethylene glycol(PEG) as disperser agent. The samples were characterized by TEM, SEM, XRD, IR and EDX. The results indicated that the products were rod-like nanoparticles with periodically regular mesopores, and their aspect ratio decreased when lowering the concentration of the silica source, template and disperser agent. If ethanol existed in the reacting system, the shape of the nanoparticles changed from rod to spheroid, further into irregular agglomerate with increase of the volume ratio of ethanol to water. The SiO2 nanorods were silanized and adsorbed Au seeds with average diameter of 3.7 nm on their surface. Then a multi