title: Stability Limits and Defect Dynamics in Ag Nanoparticles Probed by Bragg Coherent Diffractive Imaging.
abstract: Dissolution is critical to nanomaterial stability, especially for partially dealloyed nanoparticle catalysts. Unfortunately, highly active catalysts are often not stable in their reactive environments, preventing widespread application. Thus, focusing on the structure-stability relationship at the nanoscale is crucial and will likely play an important role in meeting grand challenges. Recent advances in imaging capability have come from electron, X-ray, and other techniques but tend to be limited to specific sample environments and/or two-dimensional images. Here, we report investigations into the defect-stability relationship of silver nanoparticles to voltage-induced electrochemical dissolution imaged in situ in three-dimensional detail by Bragg coherent diffractive imaging. We first determine the average dissolution kinetics by stationary probe rotating disk electrode in combination with inductively coupled plasma mass spectrometry, which allows in situ measurement of Ag+ion formation. We then observe the dissolution and redeposition processes in single nanocrystals, providing unique insight about the role of surface strain, defects, and their coupling to the dissolution chemistry. The methods developed and the knowledge gained go well beyond a "simple" silver electrochemistry and are applicable to all electrocatalytic reactions where functional links between activity and stability are controlled by structure and defect dynamics.
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: P P
authors.initials: PP
authors.lastname: Lopes
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: W
authors.initials: W
authors.lastname: Cha
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: R
authors.initials: R
authors.lastname: Harder
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: J
authors.initials: J
authors.lastname: Maser
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: E
authors.initials: E
authors.lastname: Maxey
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: M J
authors.initials: MJ
authors.lastname: Highland
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: N M
authors.initials: NM
authors.lastname: Markovic
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: S O
authors.initials: SO
authors.lastname: Hruszkewycz
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: G B
authors.initials: GB
authors.lastname: Stephenson
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: H
authors.initials: H
authors.lastname: You
authors.affiliation: Materials Science Division and ‡Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: A
authors.identifier: 0000-0003-4611-2561
authors.initials: A
authors.lastname: Ulvestad
keywords: Dissolution; coherent X-ray imaging; corrosion; defect; nanocrystal