Improved H 2 O 2 Photogeneration on KBr Doped‐Polymeric Carbon Nitride Via Optimize the Oxygen Reduction Path

Abstract The photosynthesis of hydrogen peroxide (H 2 O 2 ) from oxygen (O 2 ) represents a promising catalytic pathway, the limited efficiency of the oxygen reduction constitutes a primary barrier to enhancing production. In this content, alkali metal potassium (K + ) and Br‐doped g‐C 3 N 4 photocatalysts (K‐CN) were successfully constructed by one‐pot method. The introduction of K + is not only beneficial to the transmission of space charge and the separation efficiency of photogenerated carriers, but also promotes the efficient production of H 2 O 2 by 2e − oxygen reduction reaction. The introduction of Br − promotes O 2 converted to triplet state and triggers energy transfer process to increase 1 O 2 production, O 2 adsorption was facilitated through regulating the oxygen evolution (O 2 → 1 O 2 ), which is beneficial to the subsequent oxygen reduction process. The results showed that the H 2 O 2 yield of 0.05 K‐CN catalyst reached 26.0 mmol g −1 h −1 , which was more than 5 times that of pure g‐C 3 N 4 .