Correlation of electron-transfer rates with the surface density of states of native and anodically grown oxide films on titanium

Journal Article · Thu Sep 05 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100171a051· OSTI ID:5259764

Casillas, N; Snyder, S R; Smyrl, W H; White, H S ^[1]

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1. Univ. of Minnesota, Minneapolis (United States)

The authors report tunneling spectroscopy (TS) and surface density of states (SDOS) plots ((dI/dV)/(I/V) vs V) for native and anodically grown titanium dioxide (TiO{sub 2}) films on polycrystalline Ti. The results are compared to data obtained by using single-crystal TiO{sub 2} ((001) and (110) surface orientations). SDOS plots for anodically grown TiO{sub 2} films (160 {Angstrom} thick) and single-crystals TiO{sub 2} show a large bandgap region ({approximately}2 eV) with a low state density separating the conduction and valence band edges. The similarity in the distribution of SDOS for anodically grown TiO{sub 2} films and single-crystal TiO{sub 2} indicates that the anodically grown film has a well-ordered rutile structure. In contrast, SDOS plots obtained on native TiO{sub 2} films show a nearly constant density of states over a 5-eV range and {approximately}20-50-fold increase in state density at energies corresponding to the bandgap region of anodically grown films and single-crystal TiO{sub 2}. Electron-transfer rates for the oxidation of ferrocene in acetonitrile at native and anodically grown TiO{sub 2} films are reported and correlated with the measured SDOS of these materials.

• OSTI ID: 5259764
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:18; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
FERROCENE
ELECTRON TRANSFER
OXIDATION
TITANIUM OXIDES
ELECTRONIC STRUCTURE
ELECTROCHEMISTRY
ENERGY GAP
EXPERIMENTAL DATA
KINETICS
MATHEMATICAL MODELS
MILLER INDICES
MONOCRYSTALS
REDOX POTENTIAL
RUTILE
THEORETICAL DATA
THIN FILMS
TITANIUM
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
CRYSTALS
DATA
DIENES
ELEMENTS
FILMS
HYDROCARBONS
INFORMATION
IRON COMPLEXES
MATERIALS
METALS
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POLYENES
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400400* - Electrochemistry
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies