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Free silver nanoparticles doped by potassium : Work-function change in experiment and theory

Mikkelä, Mikko Heikki LU ; Jänkälä, Kari ; Huttula, Marko ; Björneholm, Olle LU and Tchaplyguine, Maxim LU (2021) In Journal of Chemical Physics 154(23).
Abstract

The composition-dependent change in the work-function (WF) of binary silver-potassium nanoparticles has been studied experimentally by synchrotron-based x-ray photoelectron spectroscopy (PES) and theoretically using a microscopic jellium model of metals. The Ag-K particles with different K fractions were produced by letting a beam of preformed Ag particles pass through a volume with K vapor. The PES on a beam of individual non-supported Ag-K nanoparticles created in this way allowed a direct absolute measurement of their WF, avoiding several usual shortcomings of the method. Experimentally, the WF has been found to be very sensitive to K concentration: Already at low exposure, it decreased down to ≈2 eV - below the value of pure K. In... (More)

The composition-dependent change in the work-function (WF) of binary silver-potassium nanoparticles has been studied experimentally by synchrotron-based x-ray photoelectron spectroscopy (PES) and theoretically using a microscopic jellium model of metals. The Ag-K particles with different K fractions were produced by letting a beam of preformed Ag particles pass through a volume with K vapor. The PES on a beam of individual non-supported Ag-K nanoparticles created in this way allowed a direct absolute measurement of their WF, avoiding several usual shortcomings of the method. Experimentally, the WF has been found to be very sensitive to K concentration: Already at low exposure, it decreased down to ≈2 eV - below the value of pure K. In the jellium modeling, considered for Ag-K nanoparticles, two principally different adsorption patterns were tested: without and with K diffusion. The experimental and calculation results together suggest that only efficient surface alloying of two metals, whose immiscibility was long-term textbook knowledge, could lead to the observed WF values.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
154
issue
23
article number
234708
publisher
American Institute of Physics (AIP)
external identifiers
  • pmid:34241256
  • scopus:85108279752
ISSN
0021-9606
DOI
10.1063/5.0052101
language
English
LU publication?
yes
additional info
Funding Information: This work was supported by the Swedish Research Council (VR), the Knut and Alice Wallenberg Foundation, the Crafoord Foundation, Nordforsk, and the Swedish Foundation for Strategic Research.
id
ade3143b-8227-4ba6-92a7-6ddbca85eabb
date added to LUP
2021-08-12 11:51:55
date last changed
2025-10-14 11:26:00
@article{ade3143b-8227-4ba6-92a7-6ddbca85eabb,
  abstract     = {{<p>The composition-dependent change in the work-function (WF) of binary silver-potassium nanoparticles has been studied experimentally by synchrotron-based x-ray photoelectron spectroscopy (PES) and theoretically using a microscopic jellium model of metals. The Ag-K particles with different K fractions were produced by letting a beam of preformed Ag particles pass through a volume with K vapor. The PES on a beam of individual non-supported Ag-K nanoparticles created in this way allowed a direct absolute measurement of their WF, avoiding several usual shortcomings of the method. Experimentally, the WF has been found to be very sensitive to K concentration: Already at low exposure, it decreased down to ≈2 eV - below the value of pure K. In the jellium modeling, considered for Ag-K nanoparticles, two principally different adsorption patterns were tested: without and with K diffusion. The experimental and calculation results together suggest that only efficient surface alloying of two metals, whose immiscibility was long-term textbook knowledge, could lead to the observed WF values. </p>}},
  author       = {{Mikkelä, Mikko Heikki and Jänkälä, Kari and Huttula, Marko and Björneholm, Olle and Tchaplyguine, Maxim}},
  issn         = {{0021-9606}},
  language     = {{eng}},
  number       = {{23}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Journal of Chemical Physics}},
  title        = {{Free silver nanoparticles doped by potassium : Work-function change in experiment and theory}},
  url          = {{http://dx.doi.org/10.1063/5.0052101}},
  doi          = {{10.1063/5.0052101}},
  volume       = {{154}},
  year         = {{2021}},
}