Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing
WO3 nanorods and GO (at 1 wt% loading) doped WO3 were synthesized using a template free deposition-hydrothermal route and thoroughly characterized by various techniques including XRD, FTIR, Raman, TEM-SAED, PL, UV-Vis, XPS, and N2 adsorption. The nano-materials performance was investigated toward ph...
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Frontiers Media S.A.
2019-11-01
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| Series: | Frontiers in Chemistry |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fchem.2019.00722/full |
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| author | Tarek M. Salama Mohamed Morsy Rabab M. Abou Shahba Shimaa H. Mohamed Mohamed Mokhtar Mohamed |
| author_facet | Tarek M. Salama Mohamed Morsy Rabab M. Abou Shahba Shimaa H. Mohamed Mohamed Mokhtar Mohamed |
| author_sort | Tarek M. Salama |
| collection | DOAJ |
| description | WO3 nanorods and GO (at 1 wt% loading) doped WO3 were synthesized using a template free deposition-hydrothermal route and thoroughly characterized by various techniques including XRD, FTIR, Raman, TEM-SAED, PL, UV-Vis, XPS, and N2 adsorption. The nano-materials performance was investigated toward photocatalytic degradation of methylene blue dye (20 ppm) under visible light illumination (160 W, λ> 420) and gas sensing ability for ammonia gas (10–100 ppm) at 200°C. HRTEM investigation of the 1%GO.WO3 composite revealed WO3 nanorods of a major d-spacing value of 0.16 nm indexed to the crystal plane (221). That relevant plane was absent in pure WO3 establishing the intercalation with GO. The MB degradation activity was considerably enhanced over the 1%GO.WO3 catalyst with a rate constant of 0.0154 min−1 exceeding that of WO3 by 15 times. The reaction mechanism was justified dependent on electrons, holes and •OH reactive species as determined via scavenger examination tests and characterization techniques. The drop in both band gap (2.49 eV) and PL intensity was the main reason responsible for enhancing the photo-degradation activity of the 1%GO.WO3 catalyst. The later catalyst initiated the two electron O2 reduction forming H2O2, that contributed in the photoactivity improvement via forming •OH moieties. The hexagonal structure of 1%GO.WO3 showed a better gas sensing performance for ammonia gas at 100 ppm (Ra-Rg/Rg = 17.6) exceeding that of pure WO3 nanorods (1.27). The superiority of the gas-sensing property of the 1%GO.WO3 catalyst was mainly ascribed to the high dispersity of GO onto WO3 surfaces by which different carbon species served as mediators to hinder the recombination rate of photo-generated electron-hole pairs and therefore facilitated the electron transition. The dominancy of the lattice plane (221) in 1%GO.WO3 formed between GO and WO3 improved the electron transport in the gas-sensing process. |
| first_indexed | 2024-12-22T03:15:07Z |
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| institution | Directory Open Access Journal |
| issn | 2296-2646 |
| language | English |
| last_indexed | 2024-12-22T03:15:07Z |
| publishDate | 2019-11-01 |
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| spelling | doaj.art-ddee3b5e7622432bb3a66d747948ff432022-12-21T18:40:50ZengFrontiers Media S.A.Frontiers in Chemistry2296-26462019-11-01710.3389/fchem.2019.00722467111Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas SensingTarek M. Salama0Mohamed Morsy1Rabab M. Abou Shahba2Shimaa H. Mohamed3Mohamed Mokhtar Mohamed4Department of Chemistry, Faculty of Science, Al-Azhar University, Cairo, EgyptBuilding Physics and Environment Institute, Housing and Building National Research Center (HBRC), Giza, EgyptDepartment of Chemistry, Faculty of Science (Girls Branch), Al-Azhar University, Cairo, EgyptDepartment of Chemistry, Faculty of Science (Girls Branch), Al-Azhar University, Cairo, EgyptChemistry Department, Faculty of Science, Benha University, Benha, EgyptWO3 nanorods and GO (at 1 wt% loading) doped WO3 were synthesized using a template free deposition-hydrothermal route and thoroughly characterized by various techniques including XRD, FTIR, Raman, TEM-SAED, PL, UV-Vis, XPS, and N2 adsorption. The nano-materials performance was investigated toward photocatalytic degradation of methylene blue dye (20 ppm) under visible light illumination (160 W, λ> 420) and gas sensing ability for ammonia gas (10–100 ppm) at 200°C. HRTEM investigation of the 1%GO.WO3 composite revealed WO3 nanorods of a major d-spacing value of 0.16 nm indexed to the crystal plane (221). That relevant plane was absent in pure WO3 establishing the intercalation with GO. The MB degradation activity was considerably enhanced over the 1%GO.WO3 catalyst with a rate constant of 0.0154 min−1 exceeding that of WO3 by 15 times. The reaction mechanism was justified dependent on electrons, holes and •OH reactive species as determined via scavenger examination tests and characterization techniques. The drop in both band gap (2.49 eV) and PL intensity was the main reason responsible for enhancing the photo-degradation activity of the 1%GO.WO3 catalyst. The later catalyst initiated the two electron O2 reduction forming H2O2, that contributed in the photoactivity improvement via forming •OH moieties. The hexagonal structure of 1%GO.WO3 showed a better gas sensing performance for ammonia gas at 100 ppm (Ra-Rg/Rg = 17.6) exceeding that of pure WO3 nanorods (1.27). The superiority of the gas-sensing property of the 1%GO.WO3 catalyst was mainly ascribed to the high dispersity of GO onto WO3 surfaces by which different carbon species served as mediators to hinder the recombination rate of photo-generated electron-hole pairs and therefore facilitated the electron transition. The dominancy of the lattice plane (221) in 1%GO.WO3 formed between GO and WO3 improved the electron transport in the gas-sensing process.https://www.frontiersin.org/article/10.3389/fchem.2019.00722/fullhexagonal WO3graphene oxidehydrothermal methodgas sensingMB photocatalysisvisible light irradiation |
| spellingShingle | Tarek M. Salama Mohamed Morsy Rabab M. Abou Shahba Shimaa H. Mohamed Mohamed Mokhtar Mohamed Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing Frontiers in Chemistry hexagonal WO3 graphene oxide hydrothermal method gas sensing MB photocatalysis visible light irradiation |
| title | Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing |
| title_full | Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing |
| title_fullStr | Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing |
| title_full_unstemmed | Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing |
| title_short | Synthesis of Graphene Oxide Interspersed in Hexagonal WO3 Nanorods for High-Efficiency Visible-Light Driven Photocatalysis and NH3 Gas Sensing |
| title_sort | synthesis of graphene oxide interspersed in hexagonal wo3 nanorods for high efficiency visible light driven photocatalysis and nh3 gas sensing |
| topic | hexagonal WO3 graphene oxide hydrothermal method gas sensing MB photocatalysis visible light irradiation |
| url | https://www.frontiersin.org/article/10.3389/fchem.2019.00722/full |
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