The extended π-conjugated system in polymer semiconductors holds a great potential in tuning the delocalized electrons for promoting photocatalytic efficiency. Herein, π-conjugate pyridine rings and nitrogen defects co-decorated polymer carbon nitride nanosheet (NCN-2AP-X) was constructed and applied in solar driven hydrogen (H₂) and hydrogen peroxide (H₂O₂) production. Benefiting from synergistic effect of pyridine rings and N vacancies, the synthesized NCN-2AP photocatalyst with rich delocalized electrons indicates the extended light absorption range and improved carrier separation capability, particularly favoring the photocatalytic reactions. The optimal NCN-2AP-10 displayed an excellent H₂ production rate of 2.55 mmol g⁻¹ h⁻¹ under visible-light irradiation with apparent quantum efficiency (AQE) of 9.79% at 420 nm. Moreover, a H₂O₂ production rate of 1.39 mmol L⁻¹ h⁻¹ was achieved by NCN-2AP-10 under monochromatic light (365 nm) irradiation. This work would provide a new view in designing the π-conjugated system incorporating metal-free photocatalysts for efficient H₂ and H₂O₂ production.

聚合物半导体中扩展的 π 共轭系统在调整离域电子以提高光催化效率方面具有巨大潜力。在此，构建了π-共轭吡啶环和氮缺陷共修饰聚合物氮化碳纳米片（NCN-2AP-X）并将其应用于太阳能驱动的氢（H ₂）和过氧化氢（H ₂ O ₂）生产。得益于吡啶环和N空位的协同作用，合成的NCN-2AP光催化剂具有丰富的离域电子，表明光吸收范围扩大，载流子分离能力提高，特别有利于光催化反应。最佳 NCN-2AP-10 显示出 2.55 mmol g 的出色 H ₂生产率⁻¹ h ⁻¹在可见光照射下，表观量子效率 (AQE) 在 420 nm 时为 9.79%。此外，在单色光（365 nm）照射下，NCN-2AP-10 实现了1.39 mmol L ^-1  h ^{-1的 H} ₂ O ₂生产率。这项工作将为设计包含无金属光催化剂以高效生产 H ₂和 H ₂ O ₂的 π 共轭体系提供新的视角。