Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization
Nanotube/nanowire-structured TiO2 was formed on the Ti surface by an anodic oxidation method performed at different potential values (50 or 60 V) and for different times (3 or 5 h). The TiO2 photocatalysts were taken in powder form using the ultrasonic treatment from the Ti electrodes, calcined at d...
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Frontiers Media S.A.
2022-05-01
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| Series: | Frontiers in Chemistry |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fchem.2022.856947/full |
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| author | Sıdıka Çetinkaya Gofur Khamidov Levent Özcan Leonardo Palmisano Sedat Yurdakal |
| author_facet | Sıdıka Çetinkaya Gofur Khamidov Levent Özcan Leonardo Palmisano Sedat Yurdakal |
| author_sort | Sıdıka Çetinkaya |
| collection | DOAJ |
| description | Nanotube/nanowire-structured TiO2 was formed on the Ti surface by an anodic oxidation method performed at different potential values (50 or 60 V) and for different times (3 or 5 h). The TiO2 photocatalysts were taken in powder form using the ultrasonic treatment from the Ti electrodes, calcined at different temperatures, and characterized by XRD and SEM techniques, and BET surface area analyses. Both the crystallinity and the size of the primary TiO2 particles increased by increasing the heat treatment temperature. While all the photocatalysts heat treated up to 500°C were only in the anatase phase, the particles heat-treated at 700°C consisted of both anatase and rutile phases. The BET specific surface area of the samples decreased drastically after heat treatment of 700°C because of partial sinterization. SEM analyses indicated that the prepared materials were structured in both nanotubes and nanowires. They were tested as photocatalysts for the selective oxidation of glycerol and 3-pyridinemethanol under UVA irradiation in water at room temperature and ambient pressure. Glyceraldehyde, 1,3-dihydroxyacetone, and formic acid were determined as products in glycerol oxidation, while the products of 3-pyridinemethanol oxidation were 3-pyridinemethanal and vitamin B3. Non-nanotube/nanowire-structured commercial (Degussa P25 and Merck TiO2) photocatalysts were used for the sake of comparison. Low selectivity values towards the products obtained by partial oxidation were determined for glycerol. On the contrary, higher selectivity values towards the products were obtained (total 3-pyridinemethanal and vitamin B3 selectivity up to ca. 90%) for the photocatalytic oxidation of 3-pyridinemethanol. TiO2 photocatalysts must be highly crystalline (calcined at 700°C) for effective oxidation of glycerol, while for the selective oxidation of 3-pyridinemethanol it was not necessary to obtain a high crystallinity, and the optimal heat treatment temperature was 250°C. Glycerol and its oxidation products could more easily desorb from highly crystalline and less hydroxylated surfaces, which would justifies their higher activity. The prepared photocatalysts showed lower activity than Degussa P25, but a greater selectivity towards the products found. |
| first_indexed | 2024-12-12T09:37:02Z |
| format | Article |
| id | doaj.art-8b1d1856a2b2450cad6943a66a7c611a |
| institution | Directory Open Access Journal |
| issn | 2296-2646 |
| language | English |
| last_indexed | 2024-12-12T09:37:02Z |
| publishDate | 2022-05-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Chemistry |
| spelling | doaj.art-8b1d1856a2b2450cad6943a66a7c611a2022-12-22T00:28:41ZengFrontiers Media S.A.Frontiers in Chemistry2296-26462022-05-011010.3389/fchem.2022.856947856947Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown AnodizationSıdıka Çetinkaya0Gofur Khamidov1Levent Özcan2Leonardo Palmisano3Sedat Yurdakal4Kimya Bölümü, Fen-Edebiyat Fakültesi, Afyon Kocatepe Üniversitesi, Ahmet Necdet Sezer Kampüsü, Afyonkarahisar, TurkeyKimya Bölümü, Fen-Edebiyat Fakültesi, Afyon Kocatepe Üniversitesi, Ahmet Necdet Sezer Kampüsü, Afyonkarahisar, TurkeyBiyomedikal Mühendisliği Bölümü, Mühendislik Fakültesi, Afyon Kocatepe Üniversitesi, Ahmet Necdet Sezer Kampüsü, Afyonkarahisar, TurkeySchiavello-Grillone Photocatalysis Group, Università degli Studi di Palermo, Dipartimento di Ingegneria (DI), Palermo, ItalyKimya Bölümü, Fen-Edebiyat Fakültesi, Afyon Kocatepe Üniversitesi, Ahmet Necdet Sezer Kampüsü, Afyonkarahisar, TurkeyNanotube/nanowire-structured TiO2 was formed on the Ti surface by an anodic oxidation method performed at different potential values (50 or 60 V) and for different times (3 or 5 h). The TiO2 photocatalysts were taken in powder form using the ultrasonic treatment from the Ti electrodes, calcined at different temperatures, and characterized by XRD and SEM techniques, and BET surface area analyses. Both the crystallinity and the size of the primary TiO2 particles increased by increasing the heat treatment temperature. While all the photocatalysts heat treated up to 500°C were only in the anatase phase, the particles heat-treated at 700°C consisted of both anatase and rutile phases. The BET specific surface area of the samples decreased drastically after heat treatment of 700°C because of partial sinterization. SEM analyses indicated that the prepared materials were structured in both nanotubes and nanowires. They were tested as photocatalysts for the selective oxidation of glycerol and 3-pyridinemethanol under UVA irradiation in water at room temperature and ambient pressure. Glyceraldehyde, 1,3-dihydroxyacetone, and formic acid were determined as products in glycerol oxidation, while the products of 3-pyridinemethanol oxidation were 3-pyridinemethanal and vitamin B3. Non-nanotube/nanowire-structured commercial (Degussa P25 and Merck TiO2) photocatalysts were used for the sake of comparison. Low selectivity values towards the products obtained by partial oxidation were determined for glycerol. On the contrary, higher selectivity values towards the products were obtained (total 3-pyridinemethanal and vitamin B3 selectivity up to ca. 90%) for the photocatalytic oxidation of 3-pyridinemethanol. TiO2 photocatalysts must be highly crystalline (calcined at 700°C) for effective oxidation of glycerol, while for the selective oxidation of 3-pyridinemethanol it was not necessary to obtain a high crystallinity, and the optimal heat treatment temperature was 250°C. Glycerol and its oxidation products could more easily desorb from highly crystalline and less hydroxylated surfaces, which would justifies their higher activity. The prepared photocatalysts showed lower activity than Degussa P25, but a greater selectivity towards the products found.https://www.frontiersin.org/articles/10.3389/fchem.2022.856947/fullglycerol3-pyridinemethanolnanotube structured TiO2heterogeneous photocatalysisselective oxidationvitamin B3 |
| spellingShingle | Sıdıka Çetinkaya Gofur Khamidov Levent Özcan Leonardo Palmisano Sedat Yurdakal Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization Frontiers in Chemistry glycerol 3-pyridinemethanol nanotube structured TiO2 heterogeneous photocatalysis selective oxidation vitamin B3 |
| title | Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization |
| title_full | Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization |
| title_fullStr | Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization |
| title_full_unstemmed | Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization |
| title_short | Selective Photocatalytic Oxidation of Glycerol and 3-Pyridinemethanol by Nanotube/Nanowire-Structured TiO2 Powders Obtained by Breakdown Anodization |
| title_sort | selective photocatalytic oxidation of glycerol and 3 pyridinemethanol by nanotube nanowire structured tio2 powders obtained by breakdown anodization |
| topic | glycerol 3-pyridinemethanol nanotube structured TiO2 heterogeneous photocatalysis selective oxidation vitamin B3 |
| url | https://www.frontiersin.org/articles/10.3389/fchem.2022.856947/full |
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