skip to main content

Title: Scanning tunneling microscopy and spectroscopy of titanium dioxide and iron oxide single crystals used as photoelectrodes

Studies of the surface topography and electronic structure of the title transition metal oxide semiconductors will be presented. These materials have wide application in industrial thermal catalysis, and as heterogeneous photocatalysts in photoelectrochemistry. As these processes are highly surface sensitive, a detailed understanding of the surface properties of these materials is of utmost importance in developing and improving catalytically active systems involving these oxides. The scanning tunneling microscope (STM) has been employed to examine the topography of the title oxide surfaces as prepared for photoelectrochemical application. The surface electronic structure of these oxides has been studied with STM tunneling spectroscopy (IPS) combined in a single technique, but without the constraint of an ultra high vacuum environment. Using STM tunneling spectroscopy, the local surface density of states (DOS) can be spatially resolved and mapped with nanometer resolution. Although the surfaces were in contact with air, the surface data obtained allows one to correlate surface electronic structure with topography, and identify features associated with intrabandgap surface states. These states play a very important role in interfacial charge transfer and adsorbate coordination in both gas-solid and liquid-solid interfaces.
Authors:
Publication Date:
OSTI Identifier:
7004583
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph.D.)
Publisher:
Santa Barbara, CA (United States); Univ. of California
Research Org:
California Univ., Santa Barbara, CA (United States)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 36 MATERIALS SCIENCE; IRON OXIDES; ELECTRONIC STRUCTURE; MICROSCOPY; TOPOGRAPHY; TITANIUM OXIDES; MONOCRYSTALS; SEMICONDUCTOR MATERIALS; SURFACES; TUNNEL EFFECT; CHALCOGENIDES; CRYSTALS; IRON COMPOUNDS; MATERIALS; OXIDES; OXYGEN COMPOUNDS; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS 664000* -- Atomic & Molecular Physics-- (1992-); 360202 -- Ceramics, Cermets, & Refractories-- Structure & Phase Studies