Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water
The reduction of harmful nitroaromatics to useful amino-aromatics have significant opportunities in synthetic chemistry. Here a visible-light-driven eco-friendly method for the selective reduction of aromatic nitro compounds to their corresponding amines in aqueous solution by using Ag@TiO _2 and Cu...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | Materials Research Express |
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| Online Access: | https://doi.org/10.1088/2053-1591/acece3 |
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| author | Shikharani Hazarika Pankaj Dutta Geetika Borah |
| author_facet | Shikharani Hazarika Pankaj Dutta Geetika Borah |
| author_sort | Shikharani Hazarika |
| collection | DOAJ |
| description | The reduction of harmful nitroaromatics to useful amino-aromatics have significant opportunities in synthetic chemistry. Here a visible-light-driven eco-friendly method for the selective reduction of aromatic nitro compounds to their corresponding amines in aqueous solution by using Ag@TiO _2 and CuO@TiO _2 is described. It was observed that both Ag@TiO _2 and CuO@TiO _2 are photo-catalytically more efficient compared to bare TiO _2 and CuO@TiO _2 has higher activity over Ag@TiO _2 for the said conversion. The structural and morphological characterization of the as-synthesized catalysts has been done with SEM-EDX, TEM, powder XRD, ICP-AES, XPS, Photoluminescence, and UV-vis spectroscopic techniques. The nanocomposites Ag@TiO _2 and CuO@TiO _2 exhibit pure anatase phase with average crystallite size of 5.89 nm and 5.87 nm respectively as calculated from the Debye-Scherrer equation depending on the (101) plane. UV-visible results inferred enhanced optical properties of both the synthesized catalysts and revealed a reduced band gap (3.07 eV for Ag@ TiO _2 and 2.5 eV for CuO@ TiO _2 ) as compared to neat TiO _2 (3.36 eV). Various nitro compounds were tolerated under 150 W LED as a light source (13.9 lumens for an area of 0.2 ft ^2 ) in an aqueous medium at room temperature (30 °C) using NaBH _4 as a reducing agent to access corresponding amines in satisfying yields (78%–99%). The catalyst can be separated from the reaction mixture by simple centrifugal precipitation and reused for up to six consecutive cycles without apparent loss of its catalytic activity. The products were characterized by ^1 H-NMR spectroscopic techniques and compared with authentic samples. |
| first_indexed | 2024-03-12T01:29:13Z |
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| id | doaj.art-597696f329794c9d9829634dd46de3fd |
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| issn | 2053-1591 |
| language | English |
| last_indexed | 2024-03-12T01:29:13Z |
| publishDate | 2023-01-01 |
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| series | Materials Research Express |
| spelling | doaj.art-597696f329794c9d9829634dd46de3fd2023-09-12T09:11:07ZengIOP PublishingMaterials Research Express2053-15912023-01-0110909500210.1088/2053-1591/acece3Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in waterShikharani Hazarika0https://orcid.org/0000-0001-8277-4103Pankaj Dutta1Geetika Borah2Dept. of Chemistry, Dibrugarh University , Dibrugarh, Assam, IndiaDept. of Physics, Dibrugarh University , Dibrugarh, Assam, IndiaDept. of Chemistry, Dibrugarh University , Dibrugarh, Assam, IndiaThe reduction of harmful nitroaromatics to useful amino-aromatics have significant opportunities in synthetic chemistry. Here a visible-light-driven eco-friendly method for the selective reduction of aromatic nitro compounds to their corresponding amines in aqueous solution by using Ag@TiO _2 and CuO@TiO _2 is described. It was observed that both Ag@TiO _2 and CuO@TiO _2 are photo-catalytically more efficient compared to bare TiO _2 and CuO@TiO _2 has higher activity over Ag@TiO _2 for the said conversion. The structural and morphological characterization of the as-synthesized catalysts has been done with SEM-EDX, TEM, powder XRD, ICP-AES, XPS, Photoluminescence, and UV-vis spectroscopic techniques. The nanocomposites Ag@TiO _2 and CuO@TiO _2 exhibit pure anatase phase with average crystallite size of 5.89 nm and 5.87 nm respectively as calculated from the Debye-Scherrer equation depending on the (101) plane. UV-visible results inferred enhanced optical properties of both the synthesized catalysts and revealed a reduced band gap (3.07 eV for Ag@ TiO _2 and 2.5 eV for CuO@ TiO _2 ) as compared to neat TiO _2 (3.36 eV). Various nitro compounds were tolerated under 150 W LED as a light source (13.9 lumens for an area of 0.2 ft ^2 ) in an aqueous medium at room temperature (30 °C) using NaBH _4 as a reducing agent to access corresponding amines in satisfying yields (78%–99%). The catalyst can be separated from the reaction mixture by simple centrifugal precipitation and reused for up to six consecutive cycles without apparent loss of its catalytic activity. The products were characterized by ^1 H-NMR spectroscopic techniques and compared with authentic samples.https://doi.org/10.1088/2053-1591/acece3photocatalystnitro reductionband gapAg@TiO2CuO@TiO2 |
| spellingShingle | Shikharani Hazarika Pankaj Dutta Geetika Borah Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water Materials Research Express photocatalyst nitro reduction band gap Ag@TiO2 CuO@TiO2 |
| title | Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| title_full | Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| title_fullStr | Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| title_full_unstemmed | Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| title_short | Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| title_sort | surfactant free synthesis of ag tio2 and cuo tio2 photocatalyst a comparative study of their photocatalytic activity for reduction of nitroaromatics in water |
| topic | photocatalyst nitro reduction band gap Ag@TiO2 CuO@TiO2 |
| url | https://doi.org/10.1088/2053-1591/acece3 |
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