Schneider Julian, Rohner Patrik, Galliker Patrick, Raja Shyamprasad N, Pan Ying, Tiwari Manish K, Poulikakos Dimos
Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zurich, CH-8092 Zurich, Switzerland.
Nanoscale. 2015 Jun 7;7(21):9510-9. doi: 10.1039/c4nr06964a.
Gold nanoparticles with unique electronic, optical and catalytic properties can be efficiently synthesized in colloidal suspensions and are of broad scientific and technical interest and utility. However, their orderly integration on functional surfaces and devices remains a challenge. Here we show that single gold nanoparticles can be directly grown in individually printed, stabilized metal-salt ink attoliter droplets, using a nanoscale electrohydrodynamic printing method with a stable high-frequency dripping mode. This enables controllable sessile droplet nanoreactor formation and sustenance on non-wetting substrates, despite simultaneous rapid evaporation. The single gold nanoparticles can be formed inside such reactors in situ or by subsequent thermal annealing and plasma ashing. With this non-contact technique, single particles with diameters tunable in the range of 5-35 nm and with narrow size distribution, high yield and alignment accuracy are generated on demand and patterned into arbitrary arrays. The nanoparticles feature good catalytic activity as shown by the exemplary growth of silicon nanowires from the nanoparticles and the etching of nanoholes by the printed nanoparticles.
具有独特电学、光学和催化特性的金纳米颗粒能够在胶体悬浮液中高效合成，并且具有广泛的科学技术价值和用途。然而，将它们有序整合到功能表面和器件上仍然是一项挑战。在此，我们展示了通过具有稳定高频滴注模式的纳米级电流体动力学打印方法，可以在atto升液滴中单独打印的、稳定的金属盐墨水中直接生长单个金纳米颗粒。尽管同时存在快速蒸发的情况，但这使得在不润湿的基板上能够可控地形成并维持固定液滴纳米反应器。单个金纳米颗粒可以在这种反应器中原位形成，也可以通过随后的热退火和等离子体灰化形成。利用这种非接触技术，可以按需生成直径在5-35纳米范围内可调、尺寸分布窄、产率高且对准精度高的单个颗粒，并将其图案化为任意阵列。这些纳米颗粒具有良好的催化活性，如从纳米颗粒生长硅纳米线以及印刷的纳米颗粒蚀刻纳米孔的示例所示。
