Academic Journal
Insight into the Influence of ZnO Defectivity on the Catalytic Generation of Environmentally Persistent Free Radicals in ZnO/SiO2 Systems
| العنوان: | Insight into the Influence of ZnO Defectivity on the Catalytic Generation of Environmentally Persistent Free Radicals in ZnO/SiO2 Systems |
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| المؤلفون: | D'Arienzo M., Mostoni S., Crapanzano R., Cepek C., Di Credico B., Fasoli M., Polizzi S., Vedda A., Villa I., Scotti R. |
| المساهمون: | D'Arienzo, M., Mostoni, S., Crapanzano, R., Cepek, C., Di Credico, B., Fasoli, M., Polizzi, S., Vedda, A., Villa, I., Scotti, R. |
| سنة النشر: | 2019 |
| المجموعة: | Università Ca’ Foscari Venezia: ARCA (Archivio Istituzionale della Ricerca) |
| مصطلحات موضوعية: | DIBENZO-P-DIOXINS, ZINC-OXIDE, SILICA NANOPARTICLES, BLUE LUMINESCENCE, OXYGEN VACANCIES, QUANTUM DOTS, NANOSTRUCTURES, TEMPERATURE, ADSORPTION, MODEL, Settore CHIM/02 - Chimica Fisica |
| الوصف: | The present study aims at supplying a more in-depth picture of the generation of environmentally persistent free radicals (EPFRs) from phenol (PhOH) on ZnO/SiO2 systems, by exploring the properties of ZnO nanoparticles (NPs) with different intrinsic defectivity grown on highly porous silica with a spherical (ZnO/SiO2 _S) and wormlike morphology (ZnO/SiO2_W). In detail, besides an extensive structural, morphological, and surface investigation, the occurrence of inequivalent defect centers in the samples was tracked by photoluminescence (PL) experiments, which unveiled, for ZnO/SiO2_W, intense blue emissions possibly involving radiative recombination from Z(n)(i) excited levels to the valence band or to V-Zn levels. Electron spin resonance (ESR) spectra corroborated these results and revealed a remarkably different behavior of the samples in the EPFR formation model reaction. In fact, upon PhOH contact, the ESR spectrum of ZnO/SiO2_S showed the exclusive presence of a weak isotropic signal ascribable to a PhenO(center dot) EPFR. Instead, for ZnO/SiO2_W, intense features associated with oxygen species in proximity of V-O(+), V-Zn(-), and (V-Zn(-))(2)(-) centers dominate the spectra, while a minor contribution of the PhenO(center dot) radical can be discovered only by signal simulation. These outcomes definitively envisage a role of the intrinsic defectivity of ZnO NPs on the final yield and stability of EPFR generation, with V-O(+) and V-Zn(-) defects possibly involved in dissociative adsorption or oxidation processes at the oxide surface. Although this work focuses on ZnO, it is expected to foster a critical re-examination and integration of important results on other metal oxide/silica systems already reported in the literature, offering the chance to better evaluate the dependence of EPFR generation on the oxide defects chemistry. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | STAMPA |
| اللغة: | English |
| Relation: | info:eu-repo/semantics/altIdentifier/wos/WOS:000484882500038; volume:123; issue:35; firstpage:21651; lastpage:21661; numberofpages:11; journal:JOURNAL OF PHYSICAL CHEMISTRY. C; http://hdl.handle.net/10278/3719804; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85072346602; http://pubs.acs.org/journal/jpccck |
| DOI: | 10.1021/acs.jpcc.9b06900 |
| الاتاحة: | http://hdl.handle.net/10278/3719804 https://doi.org/10.1021/acs.jpcc.9b06900 http://pubs.acs.org/journal/jpccck |
| Rights: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.919026D6 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/acs.jpcc.9b06900 |
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