Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes

Journal Article · Thu Jan 11 00:00:00 EST 2018 · Langmuir

DOI:https://doi.org/10.1021/acs.langmuir.7b02870· OSTI ID:1430422

Xiao, Dongdong ^[1]; Wu, Zhigang ^[2]; Song, Miao ^[1]; Chun, Jaehun ^[1]; Schenter, Gregory K. ^[1]; Li, Dongsheng  ^[1]

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1. Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
2. School of Science, North University of China, Taiyuan 030051, China

Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to lack of direct observation. Using an in-situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in aqueous solution through both classical monomer-by-monomer addition and non-classical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars formed via both oriented and non-oriented attachment. Our calculations, along with dynamics of the observed attachment, showed that van der Waals force overcame hydrodynamic and friction forces and drove the particles toward each other. During classical growth, an anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on {001} surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag+ near the surface and the diffusion of Ag+ from bulk to surface.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Energy Frontier Research Centers (EFRC) (United States). Interfacial Dynamics in Radioactive Environments and Materials (IDREAM)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1430422
• Report Number(s): PNNL-SA-126675; KC0203020
• Journal Information: Langmuir, Vol. 34, Issue 4; ISSN 0743-7463
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English