A5049339722- Catalytic Processes in Materials Science
- Advanced Photocatalysis Techniques
- TiO2 Photocatalysis and Solar Cells
- Catalysis and Oxidation Reactions
- ZnO doping and properties
- Advanced Chemical Physics Studies
- Luminescence Properties of Advanced Materials
- Gas Sensing Nanomaterials and Sensors
- Electronic and Structural Properties of Oxides
- Copper-based nanomaterials and applications
- Inorganic Fluorides and Related Compounds
- Radioactive element chemistry and processing
- Magnesium Oxide Properties and Applications
- Advanced Condensed Matter Physics
- Electrocatalysts for Energy Conversion
- Polymer Nanocomposite Synthesis and Irradiation
- Catalysis and Hydrodesulfurization Studies
- Advanced Nanomaterials in Catalysis
- Transition Metal Oxide Nanomaterials
- Quantum Dots Synthesis And Properties
- Polymer crystallization and properties
- Hydrogen Storage and Materials
- Zeolite Catalysis and Synthesis
- Pharmaceutical and Antibiotic Environmental Impacts
- Ammonia Synthesis and Nitrogen Reduction
University of Turin
2016-2025
National Interuniversity Consortium of Materials Science and Technology
2020-2022
Torino e-district
2020
Hospital de Clínicas Universidade Federal do Paraná
2010-2014
University of Ferrara
2013
Laboratoire de Réactivité de Surface
2010
École Normale Supérieure de Lyon
2010
Laboratoire de Chimie
2010
Sorbonne Université
2010
Université Claude Bernard Lyon 1
2010
Nitrogen-doped titanium dioxide (N-TiO2), a photocatalytic material active in visible light, has been investigated by combined experimental and theoretical approach. The contains single-atom nitrogen impurities that form either diamagnetic (Nb-) or paramagnetic (Nb*) bulk centers. Both types of Nb centers give rise to localized states the band gap oxide. relative abundance these species depends on oxidation state solid, as, upon reduction, electron transfer from Ti3+ ions Nb* results...
Electron Paramagnetic Resonance (EPR) techniques have been employed to investigate charge carrier trapping in the two main TiO2 polymorphs, anatase and rutile, with particular attention features of electron sites (formally Ti(3+) ions). The classic CW-EPR technique this case provides signals based on g tensor only. Nevertheless a systematic analysis obtained various cases (anatase surface bulk centers, regular defective sites) has performed providing useful guidelines field affected by some...
Nitrogen doped TiO2, a novel photocatalyst active in the decomposition of organic pollutants using visible light, contains two different types paramagnetic centres (neutral NO radicals and NO2(2-) type radical ions respectively) which are likely related to specific properties solid.
Recent experiments have indicated that titanium dioxide (TiO2) codoped with nitrogen and fluorine may show enhanced photocatalytic activity in the visible region respect to TiO2 doped only nitrogen. Prompted by these findings, we investigated N−F through a combined theoretical experimental study. Density functional theory (DFT) calculations been carried out both within generalized gradient approximation (GGA) using hybrid functionals accurately describe electronic structure; substitutional...
The paramagnetic defects present in pristine zirconium dioxide (ZrO2) and those formed upon reductive treatments (either annealing or UV irradiation H2) are described rationalized by the joint use of electron resonance (EPR) DFT supercell calculations. Three types Zr3+ reduced sites have been examined both bulk solid (one center) at surface (two centers). Trapping centers different from Zr ions also present, whose concentration increases annealing. A fraction these showing a symmetric signal...
Nitrogen-doped TiO2 materials were successfully prepared following three different preparation routes (sol−gel, mechanochemistry, and oxidation of TiN) characterized by X-ray diffraction, electron microscopy, various spectroscopic techniques. All samples absorb visible light, the one obtained via sol−gel, showing anatase structure, is most active in decomposition organic compounds under light. Various nitrogen-containing species have been observed materials, whose presence abundances depends...
The generation of surface charge carriers in N-doped TiO2 under various types irradiation has been investigated by electron paramagnetic resonance using an approach consisting scavenging migrated electrons and holes oxygen hydrogen, respectively. TiO2, which is moderately active photocatalytic processes visible light, forms and, at lower extent, due to the synergistic effect components (around 400 nm) near-infrared ones. radiation excites from intra band gap NOx– states conduction band,...
A systematic analysis of the reduced states in titanium dioxide matrix (anatase polymorph) has been performed coupling classic continuous wave electron paramagnetic resonance (CW-EPR) with advanced pulse-EPR techniques and introducing 17O magnetic isotope into solid. Reduced were originated various ways including valence induction via aliovalent elements (F, Nb) reducing treatments bare oxide surface reaction agents (H, Na) thermal annealing under vacuum consequent oxygen depletion. Two main...
The Ce4+↔ Ce3+ redox switch is at the basis of an all-inorganic catalytic cycle that capable mimicking activity several natural enzymes. efficiency these artificial enzymes (nanozymes) strongly depends on Ce4+/Ce3+ ratio. By capitalizing results obtained oxide/oxide model systems, we implemented a simple and effective procedure to obtain conformal TiO2@CeOx core–shell nanoparticles whose thickness controlled with single-layer precision. Since species are stabilized only interface by...
Heterogeneous photocatalysis is a promising environmentally friendly strategy for removing contaminants of emerging concern from water, with titanium dioxide being the most studied and exploited photocatalyst, thanks to its good optical electrical properties. However, one main drawbacks linked use limited absorption sunlight; several strategies have been explored enhance in visible light region and, among them, doping elements belonging lanthanoid series particularly attractive. This review...
Surface excess electrons are remarkable chemical entities that provide great opportunities for the design of new materials with precisely tuned electronic and magnetic properties. In this Account, we describe structure properties electron centers generated at surface insulating oxides. We also outline elementary mechanisms basis generation solid surfaces, setting a comparison to general problem localization in condensed media. Emphasis is given morphological aspects relative surface-trapping...
Fs+(H) color centers at the surface of MgO have been studied using a combined EPR and quantum chemical approach. are paramagnetic excess electrons where unpaired electron is trapped in anion vacancy. They formed thoroughly dehydrated (1073K) upon UV irradiation under hydrogen parallel with formation minor fractions different centers. The whole spectrum resulting from has analyzed by simulation experimental profile. characterized an axial g tensor display hyperfine interaction nucleus...
The dispersion of small amounts Ce(4+) ions in the bulk ZrO2 leads to a photoactive material sensitive visible light. This is shown by monitoring with EPR formation and reactivity photogenerated (λ > 420 nm) charge carriers. effect, as confirmed DFT calculations, due presence solid empty 4f Ce states at mid gap, which act intermediate levels double excitation mechanism. can be considered an example third-generation material.
The synthesis of a mixed CeO2–ZnO oxide results in photocatalyst active under visible light. characterization the new material shows that Ce does not enter as dopant ZnO but rather forms isolated CeO2 nanoparticles supported on surface larger particles more abundant zinc phase. obtained exhibits band gap corresponding to UV light (∼3.3 eV), nevertheless. it relevant photoactivity irradiation with photons λ > 420 nm (visible light). working hypothesis is leads charge separation and...
Copper-ceria mixed oxides are widely considered promising catalysts for oxidation reactions, especially when the participation of lattice oxygen is required. However, mechanistic understanding these catalytic systems still incomplete, due to their considerable complexity. In fact, copper doping ceria results in formation a significant number different interacting sites continuous evolution during processes. present study, pure and Cu-doped samples were deeply investigated through combined...