Nanoporous silver with controllable optical properties formed by chemical dealloying in supercritical CO2

Rachel Morrish, Anthony J. Muscat

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35 Scopus citations


Nanoporous Ag was formed by selectively etching Cu from multiphase AgCu alloys using the oxidant hydrogen peroxide and the metal chelator hexafluoroacetylacetone (hfacH, 14 mM) dissolved in supercritical CO2 (60 °C and 16 MPa). The Ag films were characterized using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and ultraviolet-visible absorption spectroscopy. Sequential oxidation and chelation produced 50-100 nm Ag ligaments that exhibited an asymmetric localized surface plasmon resonance (LSPR) peak in the green range (500-570 nm). Simultaneous oxidation and chelation produced 100-200 nm faceted Ag particles that exhibited a broader, symmetric LSPR peak centered in the red range (600-700 nm). Dealloying of phase domains containing Cu concentrations as low as 24 at % was possible. These results demonstrate a means for large-scale and low environmental footprint preparation of nanoporous metals with controllable optical properties.

Original languageEnglish (US)
Pages (from-to)3865-3870
Number of pages6
JournalChemistry of Materials
Issue number16
StatePublished - Aug 25 2009


ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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