Conference report
The 9th International Conference on Solar Energy and Applied Photochemistry SOLAR ’06; 23-27 January 2006, Cairo, Egypt
This meeting, shortly called Solar ’06, has marked a special occasion: the 10th anniversary of the Photoenergy Center at the Ain Shams University in Cairo. The spirit of this distinguished photochemical laboratory was briefly but poignantly summarized by its founding chairman, Prof. Sabry Abdel-Mottaleb as “putting light to work”. The Solar conference series, which has started in 1991, carries the same spirit, while it is recognized that successful photochemical applications go hand in hand with advancement of fundamental understanding of photoinduced processes and excited states. The Solar conferences thus became a place where researchers interested in fundamental and applied aspects of phochemistry can meet and inspire each other.
The Solar ’06 meeting was attended by ca. 200 scientists from 40 countries, who have presented 12 plenary and 15 keynote lectures, 20 oral contributions and 71 posters. The limited scope of this report does not allow us to mention all the novel and interesting scientific results and applications presented. Nevertheless, it is still possible to attempt a selection that would represent the scientific topics covered at the meeting and highlight some of the outstanding achievements.
Solar energy was one of the most discussed topics. Out of many important contributions, we may stress development of new active forms of TiO2, such as organized mesoporous films (L. Kavan, Prague) or inverse opal anatase (M. Zukalová, Prague), and new sensitizers (T. Bessho, Tokyo, Lausanne), whose design can be aided with quantum-chemical DFT calculations (S. Fantacci, Perugia). Further energy-related contributions focussed on the design and optimization of solar cells. Some newly proposed materials include ZnO (L. Znaidi, Villetaneuse) and nanostructured Si with low light reflectivity (K.-H. Chen, Taipei). Various novel concepts were used, such as liquid-crystalline organic semiconductors (T. Tani, Kanagawa-ken), light-harvesting amphipipe aggregates (S. Dähne, Berlin), water-soluble polythiophenes on semiconductor substrates (J.T. McLeskey, Richmond), or photorechargeable capacitors (K. Teshima, Yokohama).
Environmental photochemistry was another important topic: economically and technologically viable systems for air purification employing photocatalytic membranes (I.R. Bellobono, Milano), photoelectrochemical reduction of pollutants (e.g. metal ions) and destruction of bacteria or H2 generation (K. Rajeshwar, Arlington), combination of photochemical and biological processes to purify wastewater (M. Mehrvar, Toronto), or various ways to enhance efficiency of TiO2 in wastewater purification, including doping with lanthanides (M.S.A Abdel-Mottaleb, Cairo). In the field of atmospheric photochemistry, it was shown (V. Vaida, Boulder) that sunlight can induce reactions of alcohols and acids by exciting vibrational overtones of OH bonds. Synthesis of special chemicals is another area of photochemical applications, as was demonstrated for diazepine drugs (C. Wentrup, Brisbane), while new types of (semi)conducting polymers were propose for light-emitting diodes (V. Cimrová, Prague). The emerging field of nanochemistry has many photochemical and photophysical aspects. This was demonstrated by photovoltaic applications of semiconductor nanoparticles with synthetically controlled shape (M. Mohamed, Cairo) and by rich photobehavior exhibited by ~16 nm - sized tubular aggregates of carbocyanines (J. Knoester, Groningen; C. Spitz, Berlin). It was also shown that DFT can deal with computationally very demanding tasks of describing molecule-nanoparticle interactions (F. De Angelis, Perugia). New aspects of photophysical behavior can be revealed by using non-traditional media such as ionic liquids (A. Samanta, Hyderabad). Several talks have focussed on optically induced processes in molecular systems and supramolecules with possible relevance to molecular devices and sensors. Thus, interactions in rotaxanes were studied by a host of spectroscopic methods, including 2-dimensional IR spectroscopy, giving insight into the functioning of possible molecular machines (W.J. Buma, Amsterdam) or photodriven molecular shuttles (H. Tian, Shanghai). Photochemical bond opening or isomerisation was found to control (switch) molecular conductivity (M.A. Rampi, Ferrara) or photophysics of ligand-bridged Ru and Os complexes (F. Hartl, Amsterdam). New aspects of the excited state characters, relaxation and reactivity were revealed for transition-metal carbonyl-diimine complexes (A. Vl?ek, London) and organic compounds (U. Mazzucato, Perugia), where it was shown that photochemical quantum yield can depend on the particular vibronic level excited (G. Favaro,Perugia).
Solar ’06 also gave the participants an interesting overview of Egyptian photochemical research, at the Photoenergy Center, as well as other laboratories. High-quality research is carried out, for example, in environmental photochemistry (water purification), photostability of dyes, spectroscopy of drugs, photophysical and spectroscopic effects of various media and supramolecular hosts, or sensitized lanthanide phosphorescence with applications in probes. New, promising, research is being started, which combines in photochemistry, photophysics and nanochemistry. Importantly, there is an emerging young generation of Egyptian scientists who will carry on and expand this work, contributing to their country’s needs and advancing our knowledge in photosciences. This was aptly emphasized in the closing talk by Sabry Abdel-Mottaleb, introducing two of his young coworkers (S. Mona, H. Hafez, Cairo), who then gave short talks of various aspects of photocatalytic environmental remediation.
Last, but not least, the social program should be highlighted. The participants had the opportunity to visit the pyramids, admire ancient treasures at the Egyptian Museum, as well as to enjoy the conference banquet, organized as an oriental evening. Cairo is indeed an exciting place to visit, where one can immerse into the contemporary vibrant metropolis, or go back in history through the great medieval city all the way to the Old Kingdom of pyramid builders some five thousand years ago.
A. Vlcek, School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS, UK
