Graphitic carbon nitride (g-C₃N₄) exhibits moderate CO₂ photoreduction due to fast recombination of photoexcited charges and low-grade visible light absorption. Herein, we synthesized highly polymerized ultrathin g-C₃N₄ nanosheets by structural reorganization. Both experimental and theoretical calculations indicate that amino groups stabilized by hydrogen bonding networks are the easiest to remove to form a more stable bridged N-(C)₃. This procedure provides additional electron transfer channels with an extended conjugated π→π* system and buckled plane structure with activated n→π* electronic transitions. This new configuration significantly improves the separation efficiency of photoexcited charges and widens the light absorption range. As a result, the prepared g-C₃N₄ shows efficient CO₂-to-CO conversion with a CO production rate of 12.95 μmol g^-1 h^-1 under λ ≥ 420 visible light and 2 μmol g^-1 h^-1 under λ ≥ 500 visible light, respectively. This work offers a new design idea for highly active visible-light-driven g-C₃N₄ for CO₂ photoreduction.

石墨氮化碳(gC ₃ N ₄ )由于光激发电荷的快速复合和低级可见光吸收而表现出适度的CO _{2光还原。}在此，我们通过结构重组合成了高聚合超薄gC ₃ N _{4纳米片。}实验和理论计算均表明，通过氢键网络稳定的氨基最容易被去除以形成更稳定的桥联N-(C) ₃。该过程提供了额外的电子转移通道，具有扩展的共轭 π→π* 系统和具有激活的 n→π* 电子跃迁的屈曲平面结构。这种新的配置显着提高了光生电荷的分离效率并拓宽了光吸收范围。结果，制备的gC ₃ N ₄显示出有效的CO ₂转化为CO，在λ ≥ 420可见光下CO产率为12.95 μmol g ^-1 h ^-1 ，在λ 下CO产率为2 μmol g ^-1 h ^-1分别≥ 500 可见光。这项工作为高活性可见光驱动的 gC ₃ N ₄ CO提供了新的设计思路₂光还原。