Direct in Situ Observation and Analysis of the Formation of Palladium Nanocrystals with High-Index Facets

Journal Article · Fri Oct 05 00:00:00 EDT 2018 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.8b02953· OSTI ID:1476371

Gao, Wenpei; Hou, Yusheng; Hood, Zachary D.  ^[1]; Wang, Xue ^[2]; More, Karren ^[3]; Wu, Ruqian; Xia, Younan  ^[4]; Pan, Xiaoqing; Chi, Miaofang  ^[3]

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1. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
3. The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States

Synthesizing concave-structured nanoparticles (NP) with high-index surfaces offers a viable method to significantly enhance the catalytic activity of NPs. Current approaches for fabricating concave NPs, however, are limited. Exploring novel synthesis methods requires a thorough understanding of the competing mechanisms that contribute to the evolution of surface structures during NP growth. Here, by tracking the evolution of Pd nanocubes into concave NPs at atomic scale using in situ liquid cell transmission electron microscopy, our study reveals that concave-structured Pd NPs can be formed by the cointroduction of surface capping agents and halogen ions. These two chemicals jointly create a new surface energy landscape of Pd NPs, leading to the morphological transformation. In particular, Pd atoms dissociate from the {100} surfaces with the aid of Cl^-ions and preferentially redeposit to the corners and edges of the nanocubes when the capping agent polyvinylpyrrolidone is introduced, resulting in the formation of concave Pd nanocubes with distinctive high-index facets. Our work not only demonstrates a potential route for synthesizing NPs with well-defined high-index facets but also reveals the detailed atomic-scale kinetics during their formation, providing insight for future predictive synthesis.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: FG02-05ER46237
• OSTI ID: 1476371
• Alternate ID(s): OSTI ID: 1508748
• Journal Information: Nano Letters, Journal Name: Nano Letters Vol. 18 Journal Issue: 11; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
catalyst
high index
in situ transmission electron microscopy
Liquid cell
nanoparticle