Oriented Anchoring of Sulfonyl Group on Hydrophobic Interface of Carbon Nitride Lowers the Energy Barrier to Boost Photocatalytic Self‐Fenton Efficiency

ABSTRACT Graphite carbon nitride has garnered significant research interest for photocatalytic pollutant degradation. However, the slow kinetics of the oxygen reduction reaction and the high recombination rate of photogenerated charges have hindered improvements in its performance. This paper synthesizes etched and crushed carbon nitride by introducing sulfonyl groups into it. Comprehensive experimental characterization and theoretical calculation show that the sulfonyl group optimizes the electronic structure of the catalyst and promotes the separation and migration of photogenerated charges. More importantly, the sulfonyl group is directly anchored at the hydrophobic interface, reducing the reaction energy barrier while promoting the photocatalytic self‐Fenton efficiency. In addition, the modified catalyst achieved a maximum H 2 O 2 yield of 1571.63 µmol g −1 h −1 , with a high apparent quantum efficiency of 11.37% at 380nm and a solar‐to‐chemical energy conversion efficiency of 0.81%. Ciprofloxacin was degraded into non‐toxic small molecules within 30 min, and the degradation kinetic efficiency was increased by 6.04 times. The photocatalytic performance has been significantly improved. This study provides a significant strategy for adjusting the structure of photocatalysts by introducing electron‐withdrawing groups and directionally anchoring them at hydrophobic interface to enhance catalytic activity and also provides valuable insights for the design and development of highly efficient photocatalysts.