NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation
Photocatalytic water splitting for hydrogen production has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution. However, current efficiency for photocatalytic hydrogen generation has been limited due to a low separation of photogen...
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MDPI AG
2021-11-01
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| author | Dewen Zheng Heng Zhao Shanyu Wang Jinguang Hu Zhangxin Chen |
| author_facet | Dewen Zheng Heng Zhao Shanyu Wang Jinguang Hu Zhangxin Chen |
| author_sort | Dewen Zheng |
| collection | DOAJ |
| description | Photocatalytic water splitting for hydrogen production has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution. However, current efficiency for photocatalytic hydrogen generation has been limited due to a low separation of photogenerated electrons and holes. p-n heterojunction with a built-in electric field emerges as an efficient strategy for photocatalyst design to boost hydrogen evolution activities due to a spontaneous charge separation. In this work, we investigated the effect of different preparation methods on photocatalytic hydrogen production over NiO-TiO<sub>2</sub> composites. The results demonstrated that a uniform distribution of NiO on a surface of TiO<sub>2</sub> with an intimate interfacial interaction was formed by a sol-gel method, while direct calcination tended to form aggregation of NiO, thus leading to an uneven p-n heterojunction structure within a photocatalyst. NiO-TiO<sub>2</sub> composites fabricated by different methods showed enhanced hydrogen production (23.5 ± 1.2, 20.4 ± 1.0 and 8.8 ± 0.7 mmolh<sup>−1</sup>g<sup>−1</sup> for S1-20%, S2-20% and S3-10%, respectively) as compared with pristine TiO<sub>2</sub> (6.6 ± 0.7 mmolh<sup>−1</sup>g<sup>−1</sup>) and NiO (2.1 ± 0.2 mmolh<sup>−1</sup>g<sup>−1</sup>). The current work demonstrates a good example to improve photocatalytic hydrogen production by finely designing p-n heterojunction photocatalysts. |
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| spelling | doaj.art-c351ce12ebae4fd2826a036feb1e045d2023-11-23T04:08:46ZengMDPI AGCatalysts2073-43442021-11-011112142710.3390/catal11121427NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen GenerationDewen Zheng0Heng Zhao1Shanyu Wang2Jinguang Hu3Zhangxin Chen4Research Institute of Petroleum Exploration and Development (RIPED), CNPC, Beijing 100083, ChinaDepartment of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, AB T2N 1N4, CanadaResearch Institute of Petroleum Exploration and Development (RIPED), CNPC, Beijing 100083, ChinaDepartment of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, AB T2N 1N4, CanadaDepartment of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, AB T2N 1N4, CanadaPhotocatalytic water splitting for hydrogen production has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution. However, current efficiency for photocatalytic hydrogen generation has been limited due to a low separation of photogenerated electrons and holes. p-n heterojunction with a built-in electric field emerges as an efficient strategy for photocatalyst design to boost hydrogen evolution activities due to a spontaneous charge separation. In this work, we investigated the effect of different preparation methods on photocatalytic hydrogen production over NiO-TiO<sub>2</sub> composites. The results demonstrated that a uniform distribution of NiO on a surface of TiO<sub>2</sub> with an intimate interfacial interaction was formed by a sol-gel method, while direct calcination tended to form aggregation of NiO, thus leading to an uneven p-n heterojunction structure within a photocatalyst. NiO-TiO<sub>2</sub> composites fabricated by different methods showed enhanced hydrogen production (23.5 ± 1.2, 20.4 ± 1.0 and 8.8 ± 0.7 mmolh<sup>−1</sup>g<sup>−1</sup> for S1-20%, S2-20% and S3-10%, respectively) as compared with pristine TiO<sub>2</sub> (6.6 ± 0.7 mmolh<sup>−1</sup>g<sup>−1</sup>) and NiO (2.1 ± 0.2 mmolh<sup>−1</sup>g<sup>−1</sup>). The current work demonstrates a good example to improve photocatalytic hydrogen production by finely designing p-n heterojunction photocatalysts.https://www.mdpi.com/2073-4344/11/12/1427hydrogen productionphotocatalysisp-n heterojunctionNiOTiO<sub>2</sub> |
| spellingShingle | Dewen Zheng Heng Zhao Shanyu Wang Jinguang Hu Zhangxin Chen NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation Catalysts hydrogen production photocatalysis p-n heterojunction NiO TiO<sub>2</sub> |
| title | NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation |
| title_full | NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation |
| title_fullStr | NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation |
| title_full_unstemmed | NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation |
| title_short | NiO-TiO<sub>2</sub> p-n Heterojunction for Solar Hydrogen Generation |
| title_sort | nio tio sub 2 sub p n heterojunction for solar hydrogen generation |
| topic | hydrogen production photocatalysis p-n heterojunction NiO TiO<sub>2</sub> |
| url | https://www.mdpi.com/2073-4344/11/12/1427 |
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