title: Pertinent parameters in photo-generation of electrons: Comparative study of anatase-based nano-TiO2 suspensions.
abstract: In the field of solar fuel cells, the development of efficient photo-converting semiconductors remains a major challenge. A rational analysis of experimental photocatalytic results obtained with material in colloïdal suspensions is needed to access fundamental knowledge required to improve the design and properties of new materials. In this study, a simple system electron donor/nano-TiO2 is considered and examined via spin scavenging electron paramagnetic resonance as well as a panel of analytical techniques (composition, optical spectroscopy and dynamic light scattering) for selected type of nano-TiO2. Independent variables (pH, electron donor concentration and TiO2 amount) have been varied and interdependent variables (aggregate size, aggregate surface vs. volume and acid/base groups distribution) are discussed. This work shows that reliable understanding involves thoughtful combination of interdependent parameters, whereas the specific surface area seems not a pertinent parameter. The conclusion emphasizes the difficulty to identify the key features of the mechanisms governing photocatalytic properties in nano-TiO2.
authors.affiliation: Centre National de la Recherche Scientifique, UPR 22, Institut Charles Sadron, 23 rue du loess, BP 84047, 67034 Strasbourg cedex 2, France. Electronic address: david.martel@ics-cnrs.unistra.fr.
authors.forename: D
authors.initials: D
authors.lastname: Martel
authors.affiliation: Centre National de la Recherche Scientifique, UPR 22, Institut Charles Sadron, 23 rue du loess, BP 84047, 67034 Strasbourg cedex 2, France; Propriétés Optiques et Magnétiques des Architectures Moléculaires (POMAM), Institut de Chimie, UMR 7177 CNRS/Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France.
authors.forename: A
authors.initials: A
authors.lastname: Guerra
authors.affiliation: Propriétés Optiques et Magnétiques des Architectures Moléculaires (POMAM), Institut de Chimie, UMR 7177 CNRS/Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France; French EPR Federation of Research (REseau NAtional de Rpe interDisciplinaire (RENARD), Fédération IR-RPE CNRS #3443), France.
authors.forename: P
authors.initials: P
authors.lastname: Turek
authors.affiliation: Chimie des Ligands à Architecture Contrôlée (CLAC), Institut de Chimie, UMR 7177 CNRS/Université de Strasbourg, 1 rue Blaise Pascal, 67000 Strasbourg, France.
authors.forename: J
authors.initials: J
authors.lastname: Weiss
authors.affiliation: Propriétés Optiques et Magnétiques des Architectures Moléculaires (POMAM), Institut de Chimie, UMR 7177 CNRS/Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France; French EPR Federation of Research (REseau NAtional de Rpe interDisciplinaire (RENARD), Fédération IR-RPE CNRS #3443), France. Electronic address: vileno@unistra.fr.
authors.forename: B
authors.initials: B
authors.lastname: Vileno
keywords: EPR; Electron photo-generation; Fundamental study; Nano-TiO(2); Spin scavenger; Suspension