A dewetting route to grow heterostructured nanoparticles based on thin film heterojunctions

Abstract

Heterostructured nanoparticles have received considerable attention for their various applications due to their unique and tunable functionalities with respect to their individual bulk constituents. However, the current wet chemical synthesis of multicomponent heterostructured nanoparticles is rather complicated. Here, we report a simple and quick method to fabricate Co-Au dumbbell arrays by dewetting Co/Au heterojunctions on a Si substrate and demonstrate that the Co-Au dumbbells vary in size from 2 to 28 nm. We further show by chemical mapping that Co bells are covered by a pseudomorphic Au wetting layer of ∼4 Å, preventing the bells from oxidation. By controlling the thickness of metal heterojunctions and the annealing time, the morphology of the Co-Au nanoparticle is found to be transformed from the dumbbell to the core shell. This facile route is demonstrated to be useful for fabricating other metal-metal and metal-oxide heterostructures and hence holds technological promise for functional applications.

In Situ Kinetic Observations on Crystal Nucleation and Growth

“…95 The in situ experiments were carried out in a TEM under heating the thin Co@Cu thin films. This study provided a new route for the fabrication of metal-based core−shell NPs on supports, as was also confirmed in the case of the Co-Au system by Wang and Huang et al 356 Recently, a series of detailed investigations on Au@Ag, Ag@Au, Au@Pd, Au@Pd@Au, and Pt 3 Ni@Ni(OH) 2 core−shell NPs under different conditions by different in situ techniques were carried out. 163,357−359 4.2.1.…”

Templated Solid‐State Dewetting of Thin Silicon Films

“…This dewetting process is typically understood in the framework of a Rayleigh instability: under the action of the surface tension, the system tends to evolve toward a stable state by minimizing its surface area thus breaking‐up into tiny droplets . It has been addressed in liquids, polymers, and crystalline solids with various geometries and methods. Most importantly, the underlying physics has relevant implications for technological applications such as fabrication of nano‐structures via vapor–liquid–solid growth, ink‐jet printing, water purification, and much more.…”

Activation of micropore-confined sulfur within hierarchical porous carbon for lithium-sulfur batteries

“…8 V [27e29]. Wan et al reason that small sulfur molecules, S [2][3][4] , are confined in small micropores and are free of polysulfide dissolution, hence the omission of first plateau (~2.3 V) [27]. Huang et al further elaborate that solidesolid reactions occur with small micropore-confined sulfur that causes high resistance, resulting in a Li 2 S formation reaction occurring below 1.8 V with overpotential [28].…”