How g-C<sub>3</sub>N<sub>4</sub> Works and Is Different from TiO<sub>2</sub> as an Environmental Photocatalyst: Mechanistic View
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- Jonghun Lim
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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- Hyejin Kim
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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- Jihee Park
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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- Gun-Hee Moon
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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- Junie Jhon M. Vequizo
- Graduate School of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan
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- Akira Yamakata
- Graduate School of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan
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- Jinwoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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- Wonyong Choi
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
書誌事項
- 公開日
- 2019-12-03
- 資源種別
- journal article
- 権利情報
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- https://doi.org/10.15223/policy-029
- https://doi.org/10.15223/policy-037
- https://doi.org/10.15223/policy-045
- DOI
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- 10.1021/acs.est.9b05044
- 公開者
- American Chemical Society (ACS)
この論文をさがす
説明
Graphitic carbon nitride (CN) as a popular visible light photocatalyst needs to be better understood for environmental applications. The behaviors of CN as an environmental photocatalyst were systematically studied in comparison with a well-known TiO2 photocatalyst. The two photocatalysts exhibit different photocatalytic oxidation (PCO) behaviors and dependences on the experimental conditions (e.g., pH, Pt loading, and the kind of organic substrate and scavenger). The PCO of organic substrates was significantly enhanced by loading Pt on TiO2 under UV light (λ > 320 nm), whereas Pt-CN exhibited a lower PCO activity than bare CN under visible light (λ > 420 nm). While the presence of Pt enhances the charge separation in both TiO2/UV and CN/visible light systems (confirmed by transient IR absorption spectroscopic analysis), the opposite effects of Pt are ascribed to the different mechanisms of •OH generation in the two photocatalytic systems. The negative effect of Pt on CN is ascribed to the fact that Pt catalytically decomposes in situ-generated H2O2 (a main precursor of OH radical), which hinders •OH production. The production of OH radicals on CN is favored only at acidic pH but 1O2 generation is dominant in alkaline pH. The pH-dependent behaviors of reactive oxygen species generation on CN were confirmed by electron paramagnetic resonance spin trap measurements.
収録刊行物
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- Environmental Science & Technology
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Environmental Science & Technology 54 (1), 497-506, 2019-12-03
American Chemical Society (ACS)