Doping protocols have been widely investigated due to their effectiveness in tuning the energy band gaps of photocatalysts for improved photocatalytic activity. Here, we demonstrated the efficient and facile hydrogen peroxide-assisted hydrothermal reforming of melamine to synthesize a new oxygen (O)-doped precursor that was then transferred to O-doped g-C₃N₄ nanosheets, with an increased conductive band edge compared to bulk g-C₃N₄, via direct thermal polymerization. Owing to synergistic interaction between the 2D ultrathin nanosheet structure with large surface area and the enhanced conductive band edge caused by appropriate oxygen doping, the as-synthesized O-doped g-C₃N₄ nanosheets showed highly enhanced photocatalytic hydrogen evolution activity, about 10.7 times higher than pristine C₃N₄ under visible light irradiation, achieving an apparent quantum yield of 13.04% at 420 nm. Significantly, this precursor pre-doping strategy might provide a promising pathway for preparing heteroatom-doped g-C₃N₄.

中文翻译：

---

构造具有增强的导电带边缘的氧掺杂gC ₃ N ₄纳米片，以增强可见光驱动的氢逸出†

掺杂方案由于其在调节光催化剂的能带隙以改善光催化活性方面的有效性而被广泛研究。在这里，我们证明了三聚氰胺能够高效，简便地进行过氧化氢辅助的水热重整，以合成新的掺有氧（O）的前体，然后将其转移到掺O的gC ₃ N ₄纳米片中，与本体相比，导电带的边缘增加了GC ₃ ñ ₄，通过直接的热聚合。由于具有较大表面积的2D超薄纳米片结构与适当的氧掺杂导致的导电带边缘增强之间的协同相互作用，因此合成后的O掺杂gC ₃ N_4个纳米片表现出高度增强的光催化氢释放活性，在可见光照射下比原始C ₃ N ₄高约10.7倍，在420 nm下的表观量子产率为13.04％。重要的是，该前体预掺杂策略可能为制备杂原子掺杂的gC ₃ N ₄提供有希望的途径。