Bridging regulation in graphitic carbon nitride for band-structure modulation and directional charge transfer towards efficient H2 evolution under visible-light irradiation

作者：Cheng, Cheng; Mao, Liuhao; Huang, Zhenxiong; Shi, Jinwen^*; Zheng, Botong; Zhang, Yazhou; Guo, Liejin

来源：Journal of Colloid and Interface Science, 2021, 601: 220-228.

DOI：10.1016/j.jcis.2021.05.109

• Bridging structure
• Graphitic carbon nitride
• Hydrogen
• Polymerization degree
• Photocatalysis
• Solar energy

The bridging N atom in g-C3N4 structure plays a decisive role in photo-generated charge transfer because it usually confines photo-generated electrons and holes in each heptazine, thus leading to severe recombination. In this work, a kind of 2-aminoterephthalic acid-derived benzene ring group with rich pi-electrons was considered to integrate with bridging N to break the above-mentioned confining effect. On the basis of density-functional theory calculations and experimental analysis, this 2-aminoterephthalic acid-derived bridging structure facilitated to draw photo-generated charge out of heptazine unit, and its polarized asymmetric structure promoted the directional transfer of photo-generated charge carriers across adjacent heptazines, thus efficiently reducing the recombination. Meanwhile, the 2-aminoterephthalic acid-derived bridging structure also reinforced the connectivity of heptazine units in g-C3N4 framework and led to high degree of polymerization, which thus extended the pi-conjugated electronic system of g-C3N4 and modulated the band structure favoring photocatalytic hydrogen production. Consequently, a high photocatalytic H-2-production activity of 24,595 mu mol h(-1) g(cat)(-l) at was achieved on the bridging regulated g-C3N4 under visible light, with an apparent quantum yield of 48.7% at 425 nm.

• 单位
  西安交通大学; 厦门大学