1st Edition

Chemical Physics of Nanostructured Semiconductors

    Deep and detailed discussions on chemistry, chemical physics, photoelectrochemistry, photophysics, photocatalysis and possible applications of nanostructured semiconductor materials have shown increasing interest in the matter by scientists representing various research areas as well as industrial enterprises. Indeed, solar energy conversion and chemical methods for its realization became very popular again after the “great jump” of renewable energy sources between the middle of the 1970s and the beginning of the 1980s. Several excellent books have been published over the past years, however, in these books no attempt was made to approach this research area from the point of view of classical chemical physics. With this book, the editors aim: a) to generate an adequate scope of the modern trends and data obtained during the last years in the area of chemical physics of nanostructured materials, in particular, nanocrystalline semiconductors; b) to select an equal mix of scientists from Western and Eastern countries, all of them experts in their respective research areas; and c) to present to the international scientific community many interesting and important results which have been obtained by former Soviet Union researchers, but are not well known because they had originally been published in Russian books and journals. This book will be interesting and useful for scientists working in the area of semiconductor nanotechnology, photoelectrochemistry, photocatalysis, photochemistry of water and air purification, as well as for graduate and post-graduate students who are planning to join these research areas.

    Preface About the authors Chapter 1. Charge Separation in Titanium Oxide Nanocrystalline Semiconductors Revialed by Magnetic Resonance T. Rajh, O. G. Poluektov and M. C. Thurnauer Introduction Basic Mechanisms of Semiconductor-Assisted Photocatalysis Charge Separation and Carrier Trapping in TiO2 Nanoparticles Kinetic and Mechanism of the Charge Separation in TiO2 Colloid Nanoparticles as Studied by Time-Resolved EPR Technique Summary; References Chapter 2. Kinetic Peculiarities of Photocatalytic Reactions on CdS Nanocolloids D. V. Bavykin, E. N. Savinov, I. N. Martyanov and V. N. Parmon Introduction Synthesis of CdS Colloids Reaction of Interfacial Electron Transfer as the First Stage of Redox Photocatalytic Processes Luminescence Quenching of CdS Colloids Kinetics of Photocatalytic Reactions at Stationary Illumination Conclusion; References Chapter 3. Photooxidation of Water at Hematite Electrodes T. Lindgren, L. Vayssieres, H. Wang and S.-E. Lindquist Introduction General Background of Photooxidation of Water Structural and Physical Properties of Hematite Photoresponse of Hematite Materials Conclusion and Future Scopes; References Chapter 4. Photoelectrochemistry of Nanocrystalline Aggregates of Cyanine Dyes on the Semiconductor Electrodes D. V. Sviridov Introduction Spectroscopic Properties of Aggregated Cyanine dyes Effect of Aggregate Formation upon Electronic Energy Levels of Cyanine Dyes (CDs) Aggregates of Cyanine Dyes as the Sensitizing Agents in the Photoelectro-chemical Systems Photoelectrochemical Spectral Sensitization by Partially Aggregated CDs Spectral Sensitization of Semiconductor by Mixture of J-aggregated CDs Photoelectrochemical Behaviour of Thin Films of Aggregated CDs Conclusions; References Chapter 5. Physico-Chemical Properties of Novel Nanocrystalline Ruthenium Based Chalcogenide Materials N. Alonso-Vante Introduction Clusters or Particles A Non-aqueous Chemical Route of Synthesis Electrocatalysis and Photoelectrocatalysis Summary; References Chapter 6. Metal Nanoparticles on Semiconductor Surfaces: Electrochemistry and Photocatalysis A. I. Kulak Introduction Dependence of Nanoparticles Morphology and Behavior in Electron Transfer Processes on the Mean of Metal Nanophase Deposition onto Semiconductor Surface (ScS) Formation of Electronic Surface States in Semiconductor Band Gap as a Result of Deposition of Metal Particles on Semiconductor Surface Electrocatalytic Activity of Semiconductor Electrodes Modified by Surface Deposited Metal Nanophase Impedometric Investigation of Titania Electrodes Surface-Modified with Metal Particles Interaction of Metal Nanoparticles with the Associates of Donor Defects in Wide-Band-Gap n-type Semiconductors Conclusion; References Chapter 7. Photocatalysis: Electron Transfer Serving the Environment D. W. Bahnemann, R. Dillert and P. K. J. Robertson Introduction Primary Processes upon Band Gap Irradiation of Semiconductor Particles Chemical Nature of Trapped Charge Carriers Fate of Trapped Charge Carriers Conclusions; References Chapter 8. Electron Spin Resonance of Nanostructured Oxide Semiconductors A. I. Kokorin List of General Symbols Introduction EPR Signals of Oxide Semiconductors EPR of Small Molecules Adsorbed on the Semiconductor Surface Structural Aspects in the Study of Nanocrystalline Materials Vanadium Ions “Behaviour” in/on Oxide Semiconductors Other Paramagnetic Dopants Identification of Adsorbed Cun+ Ions at the TiO2 Surface and Electro-Chemical Behaviour of Copper-Modified Electrodes General Conclusions; References

    Biography

    Detlef W Bahnemann studied chemistry at the TU Berlin, Germany, where he received his Ph.D. in 1981. From 1981 to 1988 he worked as a Senior Scientist at the Hahn-Meitner-Institute (HMI) Berlin with Prof. Arnim Henglein. He joined the group of Prof. M. R. Hoffmann at the California Institute of Technology in Pasadena, USA as a Visiting Associate (1985-1987). In 1988-2002 he was a Department Head at the Institute for Solar Energy Research (ISFH) in Hannover, FRG. Since June 2002 he became an Academic Director at the Institute for Technical Chemistry of the Hannover University where he is responsible for the research field of Photochemistry and Nanotechnology. Prof. Dr. Bahnemann is Honorary Visiting Prof, at the Robert-Gordon Univ. in Aberdeen (UK), Lecturer for Physical Chemistry at the Carl-von Ossietzky University in Oldenburg, FRG. Alexander L Kokorin was born in 1947. Was graduated as a biophysicist in 1970; Ph.D. (Candidate of Sciences) in 1974; D.Sc. degree (Doctor of Sciences) in physical chemistry - in 1992. At present: Principal Researcher and Deputy Head of the Division of Kinetics and Catalysis, N. Semenov Institute of Chemical Physics of Russian Academy of Sciences, Moscow, Russia. Area of research interests: chemical methods of solar energy conversion; chemical physics of organized molecular systems, including nanosized oxide semiconductors doped with transition metal ions, and polymer-metal complexes; the study of their structure, absorptive, catalytic, photocatalytic and photoelectrochemical properties. EPR spectroscopy and spin-spin interaction between paramagnetics. He is the author and co-author of more than 170 publications, including two books and several reviews and book chapters.