Active site modulation of porous g-C3N4 nanofragment via defect assemblage for enhancing visible-light driven hydrogen evolution

作者：Yang, Chengwu; Chen, Yibo; Chen, Tingzhen; Low, Jingxiang; Rajendran, Saravanan; Zeng, Zhiyuan; Zhang, Xinyu^*; Qin, Jiaqian^*

来源：Fuel, 2023, 337: 126894.

DOI：10.1016/j.fuel.2022.126894

• Structural defect
• Cyano group
• Carbonyl group
• Hydrogen production

Poor light utilization and charge separation are the major factors that retard performance of g-C3N4 and solar conversion application to green energy. Herein, with the aim to address these issues and enhance photocatalytic hydrogen performance, we design and synthesize the modified g-C3N4 via defect assemblage of cyano group and carbonyl group. Cyano group and carbonyl group linked in the apex of heptazine unit were loaded into g-C3N4 framework, endowing g-C3N4 with extended light response range, tunable band structure and fast charge sep-aration. By experiments analysis and theoretical calculations, the such a defect assemblage can attract photo-charge from other parts of heptazine unit and serve as active sites in photocatalytic process. Therefore, the modified g-C3N4 material show a ten times higher photocatalytic hydrogen amount than the pristine one and the corresponding apparent quantum efficiency under 405 and 420 nm are 32.30 % and 17.94 %, respectively. In this work, the defect assemblage into g-C3N4 shows the potential of synergistic effect of different defects on enhancing photocatalytic performance, which can pave a new avenue for the defect engineering in photocatalysis.

• 单位
  燕山大学