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Document Type |
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Article In Journal |
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Document Title |
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A new understanding of the photocatalytic mechanism of the direct Z-scheme g-C3N4/TiO2 heterostructure A new understanding of the photocatalytic mechanism of the direct Z-scheme g-C3N4/TiO2 heterostructure |
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Subject |
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physics |
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Document Language |
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English |
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Abstract |
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Constructing a TiO2 based heterostructure is a very effective strategy for enhancing photocatalytic
performance. The details of the electronic structure, interfacial interaction, and photogenerated carrier
separation are important for explaining the photocatalytic properties of a heterostructure. Herein, the
density of states, charge distribution, and the band offset of the monolayer g-C3N4/TiO2 heterojunction
are systematically investigated through the hybrid DFT method. Results indicated that the valence band
offset and the conduction band offset of the g-C3N4/TiO2 heterostructure were 0.40 and 0.18 eV,
respectively. Interfacial interaction made the TiO2 surface with negative charge, whereas the g-C3N4
surface with positive charge, which led to the formation of a built-in electric field at the interface. Under
illumination, the built-in electric field accelerates the transfer of photoexcited electrons in the CB of TiO2
into the VB of g-C3N4, thus resulting in the photoexcited electrons and holes naturally accumulating in
the CB of g-C3N4 and the VB of TiO2, respectively. The photoexcited electrons and holes gathering in
different surface regions efficiently prolonged the lifetime of photogenerated carriers. Meanwhile,
electrons in the CB of g-C3N4 and holes in the VB of TiO2 had a stronger redox ability. Therefore, g-
C3N4/TiO2 is a direct Z-scheme photocatalyst, and the Z-scheme heterostructure mechanism can well
explain the improved photocatalytic activity of the g-C3N4/TiO2 heterostructure |
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ISSN |
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1463-9076 |
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Journal Name |
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PHYSICAL CHEMISTRY CHEMICAL PHYSICS |
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Volume |
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18 |
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Issue Number |
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45 |
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Publishing Year |
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1437 AH
2016 AD |
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Article Type |
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Article |
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Added Date |
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Monday, August 14, 2017 |
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Researchers
| J.J Liu | Liu, J.J | Investigator | Doctorate | jiaguoyu@yahoo.com |
| b Cheng | Cheng, b | Researcher | Doctorate | |
| J Yu | Yu, J | Researcher | Doctorate | |
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