A5004497771- Electronic and Structural Properties of Oxides
- TiO2 Photocatalysis and Solar Cells
- Gas Sensing Nanomaterials and Sensors
- Advanced Photocatalysis Techniques
- Catalytic Processes in Materials Science
- Advancements in Solid Oxide Fuel Cells
- Transition Metal Oxide Nanomaterials
- Copper-based nanomaterials and applications
- Nuclear materials and radiation effects
- Metal Extraction and Bioleaching
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Metallurgical Processes and Thermodynamics
- Thermal and Kinetic Analysis
- Nuclear Materials and Properties
- Catalysis and Oxidation Reactions
- Chalcogenide Semiconductor Thin Films
- ZnO doping and properties
- Advanced materials and composites
- Extraction and Separation Processes
- Advanced ceramic materials synthesis
- Glass properties and applications
- Electrochemical Analysis and Applications
- Semiconductor materials and devices
- Hybrid Renewable Energy Systems
Western Sydney University
2014-2024
University of Florida
2024
Penrith Community Hospital
2015
University of Oslo
2010
UNSW Sydney
1999-2008
Materials Science & Engineering
1999-2008
The University of Sydney
2007-2008
Australian Nuclear Science and Technology Organisation
2007
Institute of Metallurgy and Materials Science
1991-1992
The present work brings together the concepts of defect chemistry and photoelectrochemistry in order to consider TiO2-based photosensitive oxide semiconductors as photocatalysts for water purification. This paper reports most recent progress TiO2 its solid solutions with aliovalent ions forming donors acceptors. relationship between defect-related properties, such electrical photocatalytic are outlined. It is shown that reactivity, photoreactivity, related charge transfer based on determined...
The present work reports the electrical properties of high-purity single-crystal TiO(2) from measurements conductivity in temperature range 1073-1323 K and gas phases controlled oxygen activities 10(-13) to 10(5) Pa. effect activity on indicates that vacancies are predominant defects studied ranges activities. electronic ionic lattice charge compensations were revealed at low high activities, respectively. determined semiconducting quantities include: activation energy (E(sigma) = 125-205...
The mechanism of photoreactivity between the TiO(2) surface and H(2)O, related charge transfer, is considered in terms both collective local properties. It shown that effective transfer water requires presence active sites are able to provide electron holes adsorbed molecules. Titanium vacancies located at or near identified as for adsorption leading formation an complex resulting, consequence, splitting. A model proposed. This indicates TiO(2)-based photoelectrode may be enhanced through...
The present work considers the effect of crystal imperfections (point defects) on several properties TiO2 (rutile), such as semiconducting and segregation-induced surface well crystalline structure-related quantities, lattice parameter electronic structure. This defect disorder rutile its solid solutions in terms both intrinsic extrinsic defects. collected empirical data related theoretical models indicate that development oxide semiconductors with enhanced performance photocatalysts...
The present work derived defect disorder diagram representing the effect of oxygen activity on concentration both ionic and electronic defects for undoped TiO2. This was determined using equilibrium constants in work, including (i) intrinsic constant, (ii) constant formation vacancies, (iii) titanium vacancies. These are consistent with three properties independently, including: electrical conductivity, thermoelectric power change mass by thermogravimetry. may be used tailoring...
The present work reports the mobility of electronic charge carriers for well-defined TiO2. terms were determined by using electrical conductivity high-purity TiO2, including both single-crystal and polycrystalline specimens. concentrations derived from defect disorder diagrams. data indicate that transport electrons holes occurs according to band model hopping model, respectively. differences in between specimens are considered within two scenarios: (1) difference is due terms. This scenario...
Abstract The semiconducting properties of single‐crystal TiO 2 and their changes during prolonged oxidation at elevated temperatures under controlled oxygen activity were monitored using measurements electrical conductivity thermo‐electric power. Two kinetic regimes revealed: Regime I – rapid oxidation, associated with the transport vacancies, II which corresponds to titanium vacancies. present data represent first documented evidence for formation vacancies in . This finding allows...
Photocatalytic activity of oxide semiconductors is commonly considered in terms the effect band gap on light-induced performance. The present work considers a combined several key performance-related properties (KPPs) photocatalytic TiO2 (rutile), including chemical potential electrons (Fermi level), concentration surface active sites, and charge transport, addition to gap. KPPs have been modified using defect engineering. This approach led imposition different disorders associated KPPs,...
The present work reports the electrical conductivity and thermoelectric power for Nb-doped TiO(2) at elevated temperatures (1073-1298 K) in gas phase of controlled oxygen activity, 10(-14) Pa < p(O(2)) 75 kPa. It is shown that reduced conditions exhibits metallic-type conductivity. This finding paves way development high-performance photoelectrodes with substantially internal energy losses during charge transport. also determined equilibrium constant formation vacancies titanium TiO(2).
Rational design of surface properties oxide semiconductors for energy conversion requires in situ characterization.
Measurements of both electrical conductivity and thermoelectric power were used to monitor the equilibration kinetics undoped single-crystal TiO(2) during prolonged oxidation at 1123 1323 K p(O(2)) = 75 kPa. Two regimes revealed: regime I (rapid kinetics), which is rate-controlled by transport oxygen vacancies, II (slow titanium vacancies. The incorporation vacancies allows p-type be processed in a controlled manner. data determine chemical diffusion coefficient (D(chem)) associated with...