Screening of Ultra-Efficient Visible Light Catalysts via Material Modification to Activate Electron Polarization Inside the Material

The high catalytic activity of photocatalysts is greatly influenced by the efficient separation of photogenerated charge carriers. In this study, six g-C₃N₄-based COFs are designed and synthesized, and CN-203 is identified as the most efficient photocatalyst through experimental screening. Quantitative measurements reveal that singlet oxygen production is ≈100 times that of ·O₂⁻ and 5000 times that of ·OH. When combined with PMS, CN-203 exhibits degradation rates for RhB and TC that are ≈30 (k = 0.0293 s⁻¹) and 10 (k = 0.2940 min⁻¹) times faster than those of CN550(RhB, k = 0.0531 min⁻¹; TC, k = 0.0301 min⁻¹), respectively. Structural simulations and calculations show that the modified CN-203 have better electron–hole separation in the excited state, and the energy gap between HOMO and LUMO is significantly reduced after modification. The study also revealed the structure–function relationship between the modification of the same site with different functional groups and its effect on photocatalysis. Overall, this study provides valuable insights into the relationship between surface structure and photocatalytic applications.