Optical absorbance and band-gap engineering of two-dimensional locally phase-separated and homogeneous BCN monolayers

作者：Zeng, Xianghui; Chen, Hui^*; He, Xuan; Zhang, Haijun; Fang, Wei; Du, Xing; Li, Weixin; Huang, Zhaohui; Zhao, Lei^*

来源：Diamond and Related Materials, 2022, 122: 108801.

DOI：10.1016/j.diamond.2021.108801

• h-BCN
• Homogeneous
• Locally phase-separated
• HSE hybrid functional
• Photocatalytic

As a potential metal-free semiconductor photocatalyst, h-BCN has a tunable band gap between h-BN and graphite. However, the chemical uniformity of the distribution of carbon atoms makes it the focus of the great controversy on whether the h-BCN is phase-separated or homogeneous structure. Herein, we investigated the structure and electronic properties of locally phase-separated and homogeneous BCN using Heyd-Scuseria-Ernzerhof (HSE) hybrid functional method. The valuable features such as, the band structure, density of states, effective mass and optical absorption were computed to explore the role of C concentration and distribution in BCN. The results indicated that the proposed models exhibit tunable band gaps from 4.69 eV to 1.50 eV at gradient C concentration from 8.33% to 58.33%. The suitable band edge potentials, smaller effective mass and more efficient carrier transfer channels make the homogeneous BCN with C concentration of 25.00% to 58.33% particularly suitable for water splitting and CO2 reduction.