Accession Number:

ADA230101

Title:

Correlation of Electron-Transfer Rates with the Surface Density of States of Native and Anodically Grown Oxide Films on Titanium

Descriptive Note:

Technical rept. 1 Jan-31 Oct 1990,

Corporate Author:

MINNESOTA UNIV MINNEAPOLIS DEPT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCE

Report Date:

1990-11-16

Pagination or Media Count:

24.0

Abstract:

We report tunneling spectroscopy TS and surface density of states SDOS plots dIdVIV vs V for native and anodically grown titanium dioxide TiO2 film on polycrystalline Ti. The results are compared to data obtained using single crystal TiO2 001 and 110 surface orientations. SDOS plots for anodically grown TiO2 films 160A thick and single crystal TiO show a large band-gap region approx. 2eV with a low state density separating the conduction and valence band edges. The similarity in the distribution of SDOS for anodically grown film has a well-ordered rutile structure. In contrast, SDOS plots obtained on native TiO2 films show a nearly constant density of states over a 5 eV range and a approx. 25-fold increase in state density at energies corresponding to the band-gap region of anodically grown films and single crystal TiO2. Electron-transfer rates for the oxidation of ferrocene in acetonitrile at native and anodically grown TiO2 films are reported and correlated with the measured SDOS of these materials.

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE