Department of Engineering, University of Cambridge, Cambridge, UK.
Nanotechnology. 2011 Aug 5;22(31):315603. doi: 10.1088/0957-4484/22/31/315603. Epub 2011 Jul 8.
Gold-decorated silica nanoparticles were synthesized in a two-step process in which silica nanoparticles were produced by chemical vapor synthesis using tetraethylorthosilicate (TEOS) and subsequently decorated using two different gas-phase evaporative techniques. Both evaporative processes resulted in gold decoration of the silica particles. This study compares the mechanisms of particle decoration for a production method in which the gas and particles remain cool to a method in which the entire aerosol is heated. Results of transmission electron microscopy and visible spectroscopy studies indicate that both methods produce particles with similar morphologies and nearly identical absorption spectra, with peak absorption at 500-550 nm. A study of the thermal stability of the particles using heated-TEM indicates that the gold decoration on the particle surface remains stable at temperatures below 900 °C, above which the gold decoration begins to both evaporate and coalesce.
金修饰的二氧化硅纳米粒子是通过两步法合成的，其中使用四乙氧基硅烷（TEOS）通过化学气相合成生产了二氧化硅纳米粒子，然后使用两种不同的气相蒸发技术对其进行修饰。两种蒸发过程均导致了金对二氧化硅颗粒的修饰。本研究比较了气体和颗粒保持冷却的生产方法与整个气溶胶被加热的方法中颗粒修饰的机制。透射电子显微镜和可见光谱研究的结果表明，这两种方法都产生了具有相似形貌和几乎相同吸收光谱的颗粒，其峰值吸收在 500-550nm 处。使用加热 TEM 对颗粒的热稳定性进行的研究表明，在低于 900°C 的温度下，颗粒表面的金修饰保持稳定，在高于该温度时，金修饰开始蒸发和聚结。
