Photocatalytic Activities of Graphitic Carbon Nitride Powder for Water Reduction and Oxidation under Visible Light
Photocatalytic Activities of Graphitic Carbon Nitride Powder for Water Reduction and Oxidation under Visible Light
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石墨氮化碳粉末可见光下水还原和氧化的光催化活性
DOI：
10.1021/jp809119m
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发表时间：
2009-03-26
影响因子：
3.7
通讯作者：
Domen, Kazunari
中科院分区：
文献类型：
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作者：
Maeda, Kazuhiko;Wang, Xinchen;Domen, Kazunari
研究了带隙为2.7 eV的石墨碳氮化物（g-C3 N4）作为非金属光催化剂在紫外光和可见光下从水中放出H2或O2的性能。g-C3 N4催化剂在适当的牺牲电子给体或受体存在下分别表现出水还原成H-2或水氧化成O-2的活性，甚至不需要贵金属助催化剂。当双（1，5-环辛二烯）铂配合物[Pt（cod）（2）]（非离子配合物）代替H_2PtCl_6（离子配合物）作为Pt助催化剂的前体时，获得了增强的析氢活性。这种活性差异主要是由于Pt纳米颗粒在g-C3 N4上的更好的分散，这被认为是由于与制备过程中的H2 PtCl 6相比，Pt（cod）（2）更好地接近g-C3 N4表面。未改性的g-C3 N4在UV照射（λ> 300 nm）时从硝酸银水溶液中产生O-2，尽管由于g-C3 N4通过光生空穴的自分解而发生N-2释放。用RuO 2修饰g-C3 N4不仅提高了析氧活性，而且提高了对自分解的稳定性，导致稳定的可见光驱动的O-2析氧（λ> 420 nm）。
Graphitic carbon nitride (g-C3N4) with a band gap of 2.7 eV is studied as a nonmetallic photocatalyst for H-2 or O-2 evolution from water under ultraviolet (UV) and visible light. The g-C3N4 catalyst exhibits activities for water reduction into H-2 or water oxidation into O-2 in the presence of a proper sacrificial electron donor or acceptor, respectively, even without the need for precious metal cocatalysts. When bis(1,5-cyclooctadiene)platinum complex [Pt(cod)(2)] (a nonionic complex) is used as a precursor of Pt cocatalyst instead of H2PtCl6 (an ionic complex), enhanced H-2) evolution activity is acquired. This difference in activity is primarily due to the better dispersion of Pt nanoparticles on g-C3N4, which is considered to originate from the better access of Pt(cod)(2) to the g-C3N4 surface, as compared to that of H2PtCl6 in the preparation process. Unmodified g-C3N4 produces O-2 from an aqueous silver nitrate solution upon UV irradiation (lambda > 300 nm), although N-2, release due to self-decomposition of g-C3N4 by photogenerated holes takes place. Modification of g-C3N4 with RuO2, improves not only O-2 evolution activity but also stability against the self-decomposition, resulting in stable visible-light-driven O-2 evolution (lambda > 420 nm).