中国物理B ›› 2017, Vol. 26 ›› Issue (8): 87301-087301.doi: 10.1088/1674-1056/26/8/087301

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Modulating the properties of monolayer C2N: A promising metal-free photocatalyst for water splitting

Song Yu(俞松), Yong-Chao Rao(饶勇超), Xiang-Mei Duan(段香梅)   

  1. Department of Physics, Faculty of Science, Ningbo University, Ningbo 315211, China
  • 收稿日期:2017-04-10 修回日期:2017-05-08 出版日期:2017-08-05 发布日期:2017-08-05
  • 通讯作者: Xiang-Mei Duan E-mail:duanxiangmei@nbu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11574167).

Modulating the properties of monolayer C2N: A promising metal-free photocatalyst for water splitting

Song Yu(俞松), Yong-Chao Rao(饶勇超), Xiang-Mei Duan(段香梅)   

  1. Department of Physics, Faculty of Science, Ningbo University, Ningbo 315211, China
  • Received:2017-04-10 Revised:2017-05-08 Online:2017-08-05 Published:2017-08-05
  • Contact: Xiang-Mei Duan E-mail:duanxiangmei@nbu.edu.cn
  • About author:0.1088/1674-1056/26/8/
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11574167).

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摘要：

Photocatalytic water splitting has gained increasing attention, since it utilizes renewable resources, such as water and solar energy, to produce hydrogen. Using the first-principles density functional theory, we investigate the properties of the single layer C2N which was successfully synthesized. We reveal that monolayer C2N has a substantial direct band gap of 2.45 eV. To regulate its band gap, four different nonmetal elements (B, O, P, and S) on the cation and anion sites are considered. Among them, B-doped N site is the most effective one, with the lowest formation energy and a band gap of 2.01 eV. P-doped N site is the next, with a band gap of 2.08 eV, though its formation energy is higher. The band alignments with respect to the water redox levels show that, for these two dopings, the thermodynamic criterion for the overall water splitting is satisfied. We therefore predict that B- or P-doped C2N, with an appropriate band gap and an optimal band-edge position, would be a promising photocatalyst for visible-light water splitting.

关键词: C2N, metal-free photocatalyst, water splitting, doping, first-principle calculation

Abstract:

Photocatalytic water splitting has gained increasing attention, since it utilizes renewable resources, such as water and solar energy, to produce hydrogen. Using the first-principles density functional theory, we investigate the properties of the single layer C2N which was successfully synthesized. We reveal that monolayer C2N has a substantial direct band gap of 2.45 eV. To regulate its band gap, four different nonmetal elements (B, O, P, and S) on the cation and anion sites are considered. Among them, B-doped N site is the most effective one, with the lowest formation energy and a band gap of 2.01 eV. P-doped N site is the next, with a band gap of 2.08 eV, though its formation energy is higher. The band alignments with respect to the water redox levels show that, for these two dopings, the thermodynamic criterion for the overall water splitting is satisfied. We therefore predict that B- or P-doped C2N, with an appropriate band gap and an optimal band-edge position, would be a promising photocatalyst for visible-light water splitting.

Key words: C2N, metal-free photocatalyst, water splitting, doping, first-principle calculation

中图分类号:  (Surface states, band structure, electron density of states)

  • 73.20.At
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.20.Nr (Semiconductor compounds)