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356 results on '"Cappelletti, Giuseppe"'

11. How the Interplay between SnO2and Zn(II) Porphyrins Impacts on the Electronic Features of Gaseous Acetone Chemiresistors

Author

Tessore, Francesca, Pargoletti, Eleonora, Di Carlo, Gabriele, Albanese, Cecilia, Soave, Raffaella, Trioni, Mario Italo, Marelli, Federica, and Cappelletti, Giuseppe

Abstract

Herein, the integration of SnO2nanoparticles with two Zn(II) porphyrins─Zn(II) 5,10,15,20-tetraphenylporphyrin (ZnTPP) and its perfluorinated counterpart, Zn(II) 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (ZnTPPF20)─was investigated for the sensing of gaseous acetone at 120 °C, adopting three Zn-porphyrin/SnO2weight ratios (1:4, 1:32, and 1:64). For the first time, we were able to provide evidence of the correlation between the materials’ conductivity and these nanocomposites’ sensing performances, obtaining optimal results with a 1:32 ratio for ZnTPPF20/SnO2and showcasing a remarkable detection limit of 200 ppb together with a boosted sensing signal with respect to bare SnO2. To delve deeper, the combination of experimental data with density functional theory calculations unveiled an electron-donating behavior of both porphyrins when interacting with tin dioxide semiconductor, especially for the nonfluorinated one. The study suggested that the interplay between electrons injected, from the porphyrins’ highest occupied molecular orbital to SnO2conduction band, and the latter’s available electronic states has a dramatic impact to boost the chemiresistive sensing. Indeed, we highlighted that the key lies in preventing the full saturation of SnO2electronic states concomitantly increasing the materials’ conductivity: in this respect, the best compromise turned out to be the perfluorinated porphyrin. A further corroboration of our findings was obtained by illuminating the sensors during measurements with light-emitting diode (LED) light. Actually, we demonstrated that it does not have any impact on improving the sensing behavior, most probably due to the electronic oversaturation and scattering caused by LED excitation in porphyrins. Lastly, the most effective hybrids (1:32 ratio) were physicochemically characterized, confirming the physisorption of the macrocycles onto the SnO2surface. In conclusion, herein, we underscore the feasibility of customizing the porphyrin chemistry and porphyrin-to-SnO2ratio to enhance the gaseous sensing of bare metal oxides, providing valuable insights for the engineering of highly performing light-free chemiresistors.

Published
2024
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22. Studium- Psicologia e lavoro: Nuove prospettive per l'orientamento e la gestione delle competenze nello scenario attuale: Rivista bimestrale 2017 (4)

Author

Diego Balducci, Claudio D'Errico, Vincenzo Cappelletti, Giuseppe Dalla Torre, Massimo Borghesi, Antonio Scornajenghi, A. Claudio Bosio, Laura Galuppo, Silvio Ripamonti, Chiara D'Angelo, Giuseppe Scaratti, Barbara Bertani, Eleonora Reverberi, Eliana Versace, Carlo Felice Casola, Claudio Villa and Diego Balducci, Claudio D'Errico, Vincenzo Cappelletti, Giuseppe Dalla Torre, Massimo Borghesi, Antonio Scornajenghi, A. Claudio Bosio, Laura Galuppo, Silvio Ripamonti, Chiara D'Angelo, Giuseppe Scaratti, Barbara Bertani, Eleonora Reverberi, Eliana Versace, Carlo Felice Casola, Claudio Villa

Published
2017

23. Studium- I Giusti: storie e riflessioni: Rivista bimestrale 2017 (3)

Author

Marta Busani, Vincenzo Cappelletti, Giuseppe Dalla Torre, Claudia Villa, Sante Maletta, Ulianova Radice, Pietro Kuciukian, Maria Peri, Vincenzo Rizzo, Saverio A. Matrangolo, Maria Teresa Antonia Morelli, Mario Castellana, Giuseppe Guglielmi, Matthew Fforde, Alberto Barzanò and Marta Busani, Vincenzo Cappelletti, Giuseppe Dalla Torre, Claudia Villa, Sante Maletta, Ulianova Radice, Pietro Kuciukian, Maria Peri, Vincenzo Rizzo, Saverio A. Matrangolo, Maria Teresa Antonia Morelli, Mario Castellana, Giuseppe Guglielmi, Matthew Fforde, Alberto Barzanò

Published
2017

24. Photodegradation of Pollutants in Air: Enhanced Properties of Nano-TiO2 Prepared by Ultrasound

Author

Cappelletti, Giuseppe, Ardizzone, Silvia, Bianchi, Claudia, Gialanella, Stefano, Naldoni, Alberto, Pirola, Carlo, and Ragaini, Vittorio

Abstract

Abstract: Nanocrystalline TiO2 samples were prepared by promoting the growth of a sol–gel precursor, in the presence of water, under continuous (CW), or pulsed (PW) ultrasound. All the samples turned out to be made of both anatase and brookite polymorphs. Pulsed US treatments determine an increase in the sample surface area and a decrease of the crystallite size, that is also accompanied by a more ordered crystalline structure and the samples appear to be more regular and can be considered to contain a relatively low concentration of lattice defects. These features result in a lower recombination rate between electrons and holes and, therefore, in a good photocatalytic performance toward the degradation of NO x in air. The continuous mode induces, instead, the formation of surface defects (two components are present in XPS Ti 2p3/2 region) and consequently yields the best photocatalyst. The analysis of all the characterization data seems to suggest that the relevant parameter imposing the final features of the oxides is the ultrasound total energy per volume (E tot/V) and not the acoustic intensity or the pulsed/continuous mode.

Published
2024
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30. Studium - I Genocidi nella storia

Author

Paolo Pittaro, Paolo Carusi, Vincenzo Cappelletti, Giuseppe Dalla Torre, Antonio Giovanni Pesce, Claudia Villa, Cinzia Bearzot, Marco Buzzoni, Luca G. Castellin, Giuseppe D'Acunto, Lucia Dell'Asta, Giorgio Del Zanna, Emilia Di Rocco, Alessandro Galimberti, Rosaria Leonardi, Carmelo Licitra Rosa, Lau and Paolo Pittaro, Paolo Carusi, Vincenzo Cappelletti, Giuseppe Dalla Torre, Antonio Giovanni Pesce, Claudia Villa, Cinzia Bearzot, Marco Buzzoni, Luca G. Castellin, Giuseppe D'Acunto, Lucia Dell'Asta, Giorgio Del Zanna, Emilia Di Rocco, Alessandro Galimberti, Rosaria Leonardi, Carmelo Licitra Rosa, Lau

Published
2016

40. List of Contributors

Author

Bongiovanni, Roberta, primary, Bordado, J.C., additional, Buonomenna, M.G., additional, Cappelletti, Giuseppe, additional, De Graeve, I., additional, Duarte, A.P., additional, Fermo, Paola, additional, Ferraris, Sara, additional, Filipovic, Nenad, additional, Lamaka, Sviatlana V., additional, Leng, Jinsong, additional, Liang, Jie, additional, Liu, Liwu, additional, Liu, Yanju, additional, Lutz, A., additional, Lv, Xiongfei, additional, Mahltig, Boris, additional, Małgorzata, Muzyczek, additional, Mol, J.M.C., additional, Montemor, M. Fatima, additional, Montemor, M.F., additional, Nikkola, Juha, additional, Perero, Sergio, additional, Ren, Xuehong, additional, Románszki, L., additional, Ryszard, Kozlowski, additional, Snihirova, Darya, additional, Telegdi, J., additional, Terryn, H., additional, Trif, L., additional, Vitale, Alessandra, additional, and Zhang, Fenghua, additional

Published
2016
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46. Photodegradation of Pollutants in Air: Enhanced Properties of Nano-TiO2Prepared by Ultrasound

Author

Gialanella Stefano, Cappelletti Giuseppe, Ardizzone Silvia, Bianchi Claudia, Naldoni Alberto, Pirola Carlo, and Ragaini Vittorio

Subjects
US-assisted synthesis, Nanostructured TiO2, Photocatalysis, NO x degradation, Microstructural characterization, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

Abstract Nanocrystalline TiO2samples were prepared by promoting the growth of a sol–gel precursor, in the presence of water, under continuous (CW), or pulsed (PW) ultrasound. All the samples turned out to be made of both anatase and brookite polymorphs. Pulsed US treatments determine an increase in the sample surface area and a decrease of the crystallite size, that is also accompanied by a more ordered crystalline structure and the samples appear to be more regular and can be considered to contain a relatively low concentration of lattice defects. These features result in a lower recombination rate between electrons and holes and, therefore, in a good photocatalytic performance toward the degradation of NO x in air. The continuous mode induces, instead, the formation of surface defects (two components are present in XPS Ti 2p3/2region) and consequently yields the best photocatalyst. The analysis of all the characterization data seems to suggest that the relevant parameter imposing the final features of the oxides is the ultrasound total energypervolume (E tot/V) and not the acoustic intensity or the pulsed/continuous mode.

Published
2008
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