Photocatalytic H₂ generation has been believed to be a hopeful technology to deal with the current energy shortage issue. Among multifarious photocatalysts, graphitic carbon nitride (g-C₃N₄) has acquired enormous interests in virtue of its numerous advantages, such as peculiar physicochemical stability, favorable energy band structure and easy preparation. However, the insufficient light response range, low specific surface area, and inferior charge separation efficiency make its photocatalytic activity still unsatisfactory. In this work, the thermal exfoliation method was taken to prepare the thin g-C₃N₄ nanosheets with significantly improved specific surface area, which can afford more reaction sites and shorten the charge migration distance. Moreover, phosphorus (P) doping in g-C₃N₄ nanosheets can greatly expand its light absorption, improve the conductivity and charge-transfer capability. Due to the synergistic effect of these two strategies, the optimal H₂ generation performance of P-doped g-C₃N₄ nanosheets came up to 1146.8 μmol g⁻¹ h⁻¹, which improved 15, 2.94 and 2.62 times compared to those of original bulk g-C₃N₄, thermally exfoliated g-C₃N₄ and P-doped bulk g-C₃N₄, respectively. The synergistic effect will inspire the design of other photocatalytic systems to achieve the efficient photocatalytic H₂ generation activity.

人们认为光催化H ₂生成是解决当前能源短缺问题的一种有希望的技术。在各种各样的光催化剂中，石墨碳氮化物（gC ₃ N ₄）凭借其众多的优势，例如独特的理化稳定性，良好的能带结构和易于制备的优点而获得了极大的关注。然而，不足的光响应范围，低的比表面积和较差的电荷分离效率使得其光催化活性仍然不能令人满意。在这项工作中，采用热剥离法制备了薄的gC ₃ N ₄比表面积显着提高的纳米片，可以提供更多的反应位点并缩短电荷迁移距离。此外，在gC ₃ N ₄纳米片中掺杂磷（P）可以大大扩展其光吸收，提高电导率和电荷转移能力。由于这两种策略的协同作用，P掺杂的gC ₃ N ₄纳米片的最佳H ₂生成性能达到1146.8μmolg ^-1  h ^-1，与原来的相比提高了15倍，2.94倍和2.62倍块状gC ₃ N ₄，热剥离gC ₃ N ₄和掺杂P的块体gC ₃ N ₄。协同效应将启发其他光催化系统的设计，以实现有效的光催化H ₂生成活性。