Electrochemically modulated intercalation and reduction processes of nanostructured WO3 films

INOR 599

Haley Redmond, hepelmr@potsdam.edu and Maria Hepel, hepelmr@potsdam.edu. Department of Chemistry, State University of New York at Potsdam, 44 Pierrepont Ave., Potsdam, NY 13676
Electrochromic properties and optical density modulation in WO3 films have been studied to elucidate the mechanism of reversible ion intercalation and formation of color centers. The intercalation and electrostatic attachment of inorganic cations and alkyl ammonium cations to WO3 nanoparticles have been investigated using Electrochemical Quartz Crystal Nanobalance (EQCN) and spectroscopic techniques. Strong dependence of the cation ingress on the degree of cation hydration in aqueous solutions has been found. The competition of metal cation intercalation with the uptake of hydronium ions by WO3 films has been observed. The limited mass increases for some cations have been attributed to local water dissociation and hydronium ion uptake. These processes result in pH increase and WO3 reduction, the strongest effect being observed in the presence of alkyl ammonium cations. Improvements in the electrooptic switching performance of WO3 films have been achieved by shortening the solid-state diffusion paths and nanostructured film design.
 

Inorganic Electrochemistry
7:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007