Metal Nanodroplets Research Articles

Morphology Control of Nanostructures via Surface Reaction of Metal Nanodroplets

We report on the controllable synthesis of diverse nanostructures using laser ablation of a metal target in a liquid medium. The nanodroplets generated by laser ablation react with the liquid and produce various nanostructures, such as hollow nanoparticles, core-shell nanoparticles, heterostructures, nanocubes, and ordered arrays. A millisecond laser with low power density is essential for obtaining such metal nanodroplets, while the target material, the reactivity of liquid medium, and the laser frequency are decisive for controlling the morphology and size of the nanostructures produced. This green and powerful technique can be extended to different material systems for obtaining various nanostructures.

Laser synthesis of gold/oxide nanocomposites

The technique of pulsed laser ablation in liquid has been developed to achieve one-step synthesis of diverse gold/oxide nanocomposites with uniform morphology and superior dispersibility. High-speed photography and transmission electron microscopy observations reveal that many metal nanodroplets are ejected from the target immersed in the liquid medium during the ablation process. The nanodroplets adsorb oxygen and gold atoms that are decomposed in the solution, and form nanocomposites at high temperature. The nanocomposites exhibit excellent properties, such as enhanced catalytic activity with the increasing of the cycle number, and bifunctional character with optical and magnetic effects. Since the pulsed-laser-ablation-in-liquid process is free of toxic agents, the nanocomposites have unique advantages for catalysis or biotechnology.

Laser-induced transfer of metallic nanodroplets for plasmonics and metamaterial applications

A novel approach, to our knowledge, for the fabrication of metallic micro- and nanostructures based on femtosecond laser-induced transfer of metallic nanodroplets is developed. The controllable fabrication of high-quality spherical gold micro- and nanoparticles with radius of 100-800 nm is realized. In combination with the two-photon polymerization technique, this approach provides unique possibilities for the realization of plasmonic components and metamaterials. Polymer woodpile structures filled with gold nanoparticles are demonstrated. Scattering of surface plasmon polaritons on an individual spherical gold nanoparticle fabricated by the proposed method is investigated. The obtained results are supported by a numerical modeling using the Green's tensor approach.