10.1021/acs.nanolett.8b03139.s003
Biao Jin
Biao
Jin
Maria L. Sushko
Maria L.
Sushko
Zhaoming Liu
Zhaoming
Liu
Chuanhong Jin
Chuanhong
Jin
Ruikang Tang
Ruikang
Tang
In Situ Liquid Cell TEM Reveals Bridge-Induced Contact
and Fusion of Au Nanocrystals in Aqueous Solution
American Chemical Society
2018
multistep process advances
surface diffusion
solution
dehydration
Classical density
nanoparticle coalescence mechanism
nanobridge structure
theory calculations
nanocrystal
liquid-cell transmission electron microscopy
nanobridge forms
auric ions
nanoparticle coalescence
hydration layers
ab initio
grain boundary migration
Aqueous Solution
coalescence process
dynamics simulations
contact
Situ Liquid Cell TEM
Bridge-Induced Contact
2018-09-06 00:00:00
Media
https://acs.figshare.com/articles/media/In_Situ_Liquid_Cell_TEM_Reveals_Bridge-Induced_Contact_and_Fusion_of_Au_Nanocrystals_in_Aqueous_Solution/7059167
During nanoparticle
coalescence in aqueous solution, dehydration
and initial contact of particles are critically important but poorly
understood processes. In this work, we used in situ liquid-cell transmission
electron microscopy to directly visualize the coalescence process
of Au nanocrystals. It is found that the Au atomic nanobridge forms
between adjacent nanocrystals that are separated by a ∼0.5
nm hydration layer. The nanobridge structure first induces initial
contact of Au nanocrystals over their hydration layers and then surface
diffusion and grain boundary migration to rearrange into a single
nanocrystal. Classical density functional theory calculations and
ab initio molecular dynamics simulations suggest that the formation
of the nanobridge can be attributed to the accumulation of auric ions
and a higher local supersaturation in the gap, which can promote dehydration,
contact, and fusion of Au nanocrystals. The discovery of this multistep
process advances our understanding of the nanoparticle coalescence
mechanism in aqueous solutions.