Search

Your search keyword '"Germani, Raimondo"' showing total 551 results
Start Over Author "Germani, Raimondo"
551 results on '"Germani, Raimondo"'

12. Effect of Halide Ions on the TiO2-mediated Photocatalysis of Carbendazim in Aqueous Medium Under Near-ultraviolet Light Irradiation.

Author

Bragetta, Margherita, Germani, Raimondo, Tiecco, Matteo, Alabed, Husam B. R., and Del Giacco, Tiziana

Subjects
CARBENDAZIM, CHARGE exchange, TITANIUM dioxide, PHOTOCATALYSIS, BROMIDES, PHOTODEGRADATION, IRRADIATION
Abstract

The degradation of carbendazim (CBZ) through TiO2 photocatalysis, in the presence of halide ions and under near-UV light irradiation, was investigated. HPLC–MS technique was used to characterize the photoproducts. Spectrophotometric analysis showed that CBZ degraded slowly in TiO2 aqueous dispersions containing no salt (CBZ conversion of 6% after ca. 5 h of irradiation). The photodegradation efficiency increased particularly by addition of bromide salts. Indeed, CBZ reached complete degradation after ca. 30 min at the maximum concentration of NaBr used (0.05 M). Two significant aspects have emerged from the data analysis: the bromide role is to cause inhibition of the electron–hole recombination, a reaction known to be competitive with the reactive process; CBZ photodegradation is especially initiated by direct hole transfer pathway, whereas the OH• role is crucial in the catalyst regeneration process. Degradation attempts under sunlight appeared promising for a more sustainable photocatalytic process. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

19. Switching the three-component Biginelli-like reaction conditions for the regioselective synthesis of new 2-amino[1,2,4]triazolo[1,5-a]pyrimidines

Author

Pacetti, Martina, primary, Pismataro, Maria Chiara, additional, Felicetti, Tommaso, additional, Giammarino, Federica, additional, Bonomini, Anna, additional, Tiecco, Matteo, additional, Bertagnin, Chiara, additional, Barreca, Maria Letizia, additional, Germani, Raimondo, additional, Cecchetti, Violetta, additional, Vicenti, Ilaria, additional, Tabarrini, O, additional, Zazzi, Maurizio, additional, Loregian, Arianna, additional, and Massari, Serena, additional

Published
2024
Full Text
View/download PDF

50. Kinetic effects of cationic surfactants on the photocatalytic degradation of anionic dyes in aqueous TiO2 dispersions.

Author

Germani, Raimondo, Mancinelli, Matteo, Roselli, Arianna, Tiecco, Matteo, Fantacci, Simona, di Bona, Stefano, and Del Giacco, Tiziana

Subjects
*PHOTODEGRADATION, *CATIONIC surfactants, *DISPERSION (Chemistry), *GIBBS' free energy, *MOLECULAR shapes, *BOLTZMANN factor, *DENSITY functional theory
Abstract

In this study, oxidative degradation of Orange G (OG) and Eosin Y (EY) dyes with TiO2 as the catalyst was explored in air-equilibrated aqueous dispersions under UV light irradiation. To determine the optimal operating conditions for degradation, various effects were investigated, such as the pH of the dye dispersion, the addition of cationic surfactants and the specific additive. The photodegradation efficiency of both dyes was significantly enhanced at alkaline pH, particularly in the presence of tetraalkylammonium bromide surfactants, as they promote a mutual interaction between the dye and TiO2 surface, otherwise prevented due to their negative charge under basic conditions. The surfactant concentration also played an important role, because it influences the state of surfactant aggregation on the semiconductor surface. The kinetic trend of the fragmentation process was strongly affected by different hydrophobic and electrostatic interactions that OG and EY and their derivative intermediates are able to establish with surfactant/TiO2 in various forms of aggregation, as well as by their redox properties. Density functional theory (DFT) calculations of charge distribution and Gibbs free energy changes of solvation, performed on optimized molecular geometry, were useful to support and rationalize the surfactant involvement in the degradation process. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results