Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation
The development of visible-light-responsive (VLR) semiconductor materials for effective water oxidation is significant for a sustainable and better future. Among various candidates, bismuth tungstate (Bi<sub>2</sub>WO<sub>6</sub>; BWO) has attracted extensive attention becaus...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-08-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/17/2438 |
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| author | Tamer M. Khedr Said M. El-Sheikh Ewa Kowalska |
| author_facet | Tamer M. Khedr Said M. El-Sheikh Ewa Kowalska |
| author_sort | Tamer M. Khedr |
| collection | DOAJ |
| description | The development of visible-light-responsive (VLR) semiconductor materials for effective water oxidation is significant for a sustainable and better future. Among various candidates, bismuth tungstate (Bi<sub>2</sub>WO<sub>6</sub>; BWO) has attracted extensive attention because of many advantages, including efficient light-absorption ability, appropriate redox properties (for O<sub>2</sub> generation), adjustable morphology, low cost, and profitable chemical and optical characteristics. Accordingly, a facile solvothermal method has been proposed in this study to synthesize two-dimensional (2D) BWO nanoplates after considering the optimal preparation conditions (solvothermal reaction time: 10–40 h). To find the key factors of photocatalytic performance, various methods and techniques were used for samples’ characterization, including XRD, FE-SEM, STEM, TEM, HRTEM, BET-specific surface area measurements, UV/vis DRS, and PL spectroscopy, and photocatalytic activity was examined for water oxidation under UV and/or visible-light (vis) irradiation. Famous commercial photocatalyst–P25 was used as a reference sample. It was found that BWO crystals grew anisotropically along the {001} basal plane to form nanoplates, and all properties were controlled simultaneously by tuning the synthesis time. Interestingly, the most active sample (under both UV and vis), prepared during the 30 h solvothermal reaction at 433 K (BWO–30), was characterized by the smallest specific surface area and the largest crystals. Accordingly, it is proposed that improved crystallinity (which hindered charge carriers’ recombination, as confirmed by PL), efficient photoabsorption (using the smallest bandgap), and 2D mesoporous structure are responsible for the best photocatalytic performance of the BWO–30 sample. This report shows for the first time that 2D mesoporous BWO nanoplates might be successfully prepared through a facile template-free solvothermal approach. All the above-mentioned advantages suggest that nanostructured BWO is a prospective candidate for photocatalytic applications under natural solar irradiation. |
| first_indexed | 2024-03-10T23:16:30Z |
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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-03-10T23:16:30Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-89573b5936804cbdb628f76243ce89352023-11-19T08:36:41ZengMDPI AGNanomaterials2079-49912023-08-011317243810.3390/nano13172438Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water OxidationTamer M. Khedr0Said M. El-Sheikh1Ewa Kowalska2Institute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, JapanNanomaterials and Nanotechnology Department, Central Metallurgical Research and Development Institute (CMRDI), P.O. Box 87 Helwan, Cairo 11421, EgyptInstitute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, JapanThe development of visible-light-responsive (VLR) semiconductor materials for effective water oxidation is significant for a sustainable and better future. Among various candidates, bismuth tungstate (Bi<sub>2</sub>WO<sub>6</sub>; BWO) has attracted extensive attention because of many advantages, including efficient light-absorption ability, appropriate redox properties (for O<sub>2</sub> generation), adjustable morphology, low cost, and profitable chemical and optical characteristics. Accordingly, a facile solvothermal method has been proposed in this study to synthesize two-dimensional (2D) BWO nanoplates after considering the optimal preparation conditions (solvothermal reaction time: 10–40 h). To find the key factors of photocatalytic performance, various methods and techniques were used for samples’ characterization, including XRD, FE-SEM, STEM, TEM, HRTEM, BET-specific surface area measurements, UV/vis DRS, and PL spectroscopy, and photocatalytic activity was examined for water oxidation under UV and/or visible-light (vis) irradiation. Famous commercial photocatalyst–P25 was used as a reference sample. It was found that BWO crystals grew anisotropically along the {001} basal plane to form nanoplates, and all properties were controlled simultaneously by tuning the synthesis time. Interestingly, the most active sample (under both UV and vis), prepared during the 30 h solvothermal reaction at 433 K (BWO–30), was characterized by the smallest specific surface area and the largest crystals. Accordingly, it is proposed that improved crystallinity (which hindered charge carriers’ recombination, as confirmed by PL), efficient photoabsorption (using the smallest bandgap), and 2D mesoporous structure are responsible for the best photocatalytic performance of the BWO–30 sample. This report shows for the first time that 2D mesoporous BWO nanoplates might be successfully prepared through a facile template-free solvothermal approach. All the above-mentioned advantages suggest that nanostructured BWO is a prospective candidate for photocatalytic applications under natural solar irradiation.https://www.mdpi.com/2079-4991/13/17/2438aurivillius phase perovskitebismuth tungstatenanoplatesmesoporous materialsO<sub>2</sub> generation |
| spellingShingle | Tamer M. Khedr Said M. El-Sheikh Ewa Kowalska Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation Nanomaterials aurivillius phase perovskite bismuth tungstate nanoplates mesoporous materials O<sub>2</sub> generation |
| title | Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation |
| title_full | Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation |
| title_fullStr | Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation |
| title_full_unstemmed | Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation |
| title_short | Bismuth Tungstate Nanoplates—Vis Responsive Photocatalyst for Water Oxidation |
| title_sort | bismuth tungstate nanoplates vis responsive photocatalyst for water oxidation |
| topic | aurivillius phase perovskite bismuth tungstate nanoplates mesoporous materials O<sub>2</sub> generation |
| url | https://www.mdpi.com/2079-4991/13/17/2438 |
| work_keys_str_mv | AT tamermkhedr bismuthtungstatenanoplatesvisresponsivephotocatalystforwateroxidation AT saidmelsheikh bismuthtungstatenanoplatesvisresponsivephotocatalystforwateroxidation AT ewakowalska bismuthtungstatenanoplatesvisresponsivephotocatalystforwateroxidation |