Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles
The sonocatalytic degradation of EDTA (C0 = 5 10−3 M) in aqueous solutions was studied under 345 kHz (Pac = 0.25 W mL−1) ultrasound at 22–51 °C, Ar/20%O2, Ar or air, and in the presence of metallic titanium (Ti0) or core-shell Ti@TiO2 nanoparticles (NPs). Ti@TiO2 NPs have been obtained using simulta...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-01-01
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| Series: | Ultrasonics Sonochemistry |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1350417720301103 |
| _version_ | 1818857238348955648 |
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| author | Sara El Hakim Tony Chave Sergey I. Nikitenko |
| author_facet | Sara El Hakim Tony Chave Sergey I. Nikitenko |
| author_sort | Sara El Hakim |
| collection | DOAJ |
| description | The sonocatalytic degradation of EDTA (C0 = 5 10−3 M) in aqueous solutions was studied under 345 kHz (Pac = 0.25 W mL−1) ultrasound at 22–51 °C, Ar/20%O2, Ar or air, and in the presence of metallic titanium (Ti0) or core-shell Ti@TiO2 nanoparticles (NPs). Ti@TiO2 NPs have been obtained using simultaneous action of hydrothermal conditions (100–214 °C, autogenic pressure P = 1.0–19.0 bar) and 20 kHz ultrasound, called sonohydrothermal (SHT) treatment, on Ti0 NPs in pure water. Ti0 is composed of quasi-spherical particles (30–150 nm) of metallic titanium coated with a metastable titanium suboxide Ti3O. SHT treatment at 150–214 °C leads to the oxidation of Ti3O and partial oxidation of Ti0 and formation of nanocrystalline shell (10–20 nm) composed of TiO2 anatase. It was found that Ti0 NPs do not exhibit catalytic activity in the absence of ultrasound. Moreover, Ti0 NPs remain inactive under ultrasound in the absence of oxygen. However, significant acceleration of EDTA degradation was achieved during sonication in the presence of Ti0 NPs and Ar/20%O2 gas mixture. Coating of Ti0 with TiO2 nanocrystalline shell reduces sonocatalytic activity. Pristine TiO2 anatase nanoparticles do not show a sonocatalytic activity in studied system. Suggested mechanism of EDTA sonocatalytic degradation involves two reaction pathways: (i) sonochemical oxidation of EDTA by OH·/HO2· radicals in solution and (ii) EDTA oxidation at the surface of Ti0 NPs in the presence of oxygen activated by cavitation event. Ultrasonic activation most probably occurs due to the local heating of Ti0/O2 species at cavitation bubble/solution interface. |
| first_indexed | 2024-12-19T08:37:13Z |
| format | Article |
| id | doaj.art-04eee7757f53452eb0c92c7f4bc40133 |
| institution | Directory Open Access Journal |
| issn | 1350-4177 |
| language | English |
| last_indexed | 2024-12-19T08:37:13Z |
| publishDate | 2021-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ultrasonics Sonochemistry |
| spelling | doaj.art-04eee7757f53452eb0c92c7f4bc401332022-12-21T20:29:01ZengElsevierUltrasonics Sonochemistry1350-41772021-01-0170105336Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticlesSara El Hakim0Tony Chave1Sergey I. Nikitenko2ICSM, Univ Montpellier, UMR 5257, CEA-CNRS-UM-ENSCM, Marcoule, FranceICSM, Univ Montpellier, UMR 5257, CEA-CNRS-UM-ENSCM, Marcoule, FranceCorresponding author.; ICSM, Univ Montpellier, UMR 5257, CEA-CNRS-UM-ENSCM, Marcoule, FranceThe sonocatalytic degradation of EDTA (C0 = 5 10−3 M) in aqueous solutions was studied under 345 kHz (Pac = 0.25 W mL−1) ultrasound at 22–51 °C, Ar/20%O2, Ar or air, and in the presence of metallic titanium (Ti0) or core-shell Ti@TiO2 nanoparticles (NPs). Ti@TiO2 NPs have been obtained using simultaneous action of hydrothermal conditions (100–214 °C, autogenic pressure P = 1.0–19.0 bar) and 20 kHz ultrasound, called sonohydrothermal (SHT) treatment, on Ti0 NPs in pure water. Ti0 is composed of quasi-spherical particles (30–150 nm) of metallic titanium coated with a metastable titanium suboxide Ti3O. SHT treatment at 150–214 °C leads to the oxidation of Ti3O and partial oxidation of Ti0 and formation of nanocrystalline shell (10–20 nm) composed of TiO2 anatase. It was found that Ti0 NPs do not exhibit catalytic activity in the absence of ultrasound. Moreover, Ti0 NPs remain inactive under ultrasound in the absence of oxygen. However, significant acceleration of EDTA degradation was achieved during sonication in the presence of Ti0 NPs and Ar/20%O2 gas mixture. Coating of Ti0 with TiO2 nanocrystalline shell reduces sonocatalytic activity. Pristine TiO2 anatase nanoparticles do not show a sonocatalytic activity in studied system. Suggested mechanism of EDTA sonocatalytic degradation involves two reaction pathways: (i) sonochemical oxidation of EDTA by OH·/HO2· radicals in solution and (ii) EDTA oxidation at the surface of Ti0 NPs in the presence of oxygen activated by cavitation event. Ultrasonic activation most probably occurs due to the local heating of Ti0/O2 species at cavitation bubble/solution interface.http://www.sciencedirect.com/science/article/pii/S1350417720301103SonochemistrySonocatalysisEDTATitanium nanoparticlesHeterogeneous catalysis |
| spellingShingle | Sara El Hakim Tony Chave Sergey I. Nikitenko Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles Ultrasonics Sonochemistry Sonochemistry Sonocatalysis EDTA Titanium nanoparticles Heterogeneous catalysis |
| title | Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles |
| title_full | Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles |
| title_fullStr | Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles |
| title_full_unstemmed | Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles |
| title_short | Sonocatalytic degradation of EDTA in the presence of Ti and Ti@TiO2 nanoparticles |
| title_sort | sonocatalytic degradation of edta in the presence of ti and ti tio2 nanoparticles |
| topic | Sonochemistry Sonocatalysis EDTA Titanium nanoparticles Heterogeneous catalysis |
| url | http://www.sciencedirect.com/science/article/pii/S1350417720301103 |
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