1. Photocatalytic water splitting of (F, Ti) codoped heptazine/triazine based g-C3N4 heterostructure: A hybrid DFT study.
- Author
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Zhao, Yali, Lin, Yanming, Wang, Guanshi, Jiang, Zhenyi, Zhang, Ruiqin, and Zhu, Chaoyuan
- Subjects
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PHOTOCATALYSIS , *WATER electrolysis , *DOPED semiconductors , *TRIAZINES , *HETEROSTRUCTURES , *DENSITY functional theory - Abstract
Graphical abstract Highlights • F&Ti codoped heptazine/triazine g-C 3 N 4 heterostructure is explored by hybrid DFT. • F&Ti codoping induces a narrow bandgap of heptazine/triazine g-C 3 N 4 heterostructure. • The formed type-II heterostructure promotes the separation of electron-hole pairs. • F&Ti codoped heptazine/triazine g-C 3 N 4 has enough redox potential as photocatalyst. Abstract Graphitic carbon nitride (g-C 3 N 4) has been widely investigated as a metal-free photocatalyst for water splitting. However, the rapid recombination of photoexcited carriers and narrow visible-light response region substantially limit its performance. In this work, we have systematically studied the geometrical, electronic, optical, charge transfer and photocatalytic mechanism of (F, Ti) codoped heptazine/triazine based g-C 3 N 4 heterostructure using hybrid density functional approach. The interface interaction between heptazine and triazine g-C 3 N 4 shows heptazine and triazine g-C 3 N 4 form a Van Der Waals heterostructure. The bandgap of (F, Ti) codoped heptazine/triazine based g-C 3 N 4 heterostructure is narrow (2.39 eV), which enhances the absorption of visible light and leads to an obvious redshift of absorption edge. A type-II heterostructure is formed at the interface of (F, Ti) codoped heptazine/triazine based g-C 3 N 4 heterostructure, and leads to high photocatalytic activity. Furthermore, Bader charge and charge density difference indicate that the internal electric field promotes the separation of electron-hole pairs in the heptazine/triazine g-C 3 N 4 interface and inhibits carrier recombination. Meanwhile, electrons in the conduction band of triazine g-C 3 N 4 and holes in the valence band of (F, Ti) codoped heptazine g-C 3 N 4 have enough redox ability. This work is helpful in understanding the mechanism of photocatalytic water splitting and relevant experimental observations. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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