Revealing the Nature of Cyano Groups Modified K, O Codoped Graphitic Carbon Nitride Toward Optimized Photocatalytic H 2 and H 2 O 2 Evolution

Abstract The rapid charge separation and adequate surface‐active sites are key points for photocatalytic H 2 and H 2 O 2 evolution simultaneously. Here, cyano groups modified K, O codoped graphitic carbon nitride (KOCCN‐X) is prepared through a thermal polymerization process utilizing KOH and urea as precursors. The resultant KOCCN‐X exhibits obviously increased H 2 and H 2 O 2 evolution, and the KOCCN‐0.5 demonstrates the optimal photocatalytic performance, achieving H 2 and H 2 O 2 production rates of 4.58 and 3.56 mmol g −1  h −1 , which are ≈7.9 and 6.5 times higher than pristine g‐C 3 N 4 (CN), respectively. The structural analysis proves that K is doped at the layers of CN to form interlayer bridging via K–N coordination. O atom substitutes the N atom within the C─N═C bond in the formation of C─O─C linkage, and the cyano group is located at the edge of CN. Theoretical and experimental analysis ascertain that the interlayer bridging via K–N coordination acts as efficient electron migration channels, O and cyano groups can serve as active sites for H 2 O 2 and H 2 production, respectively. The synergistic interplay between K, O, and cyano groups effectively boosts the photocatalytic H 2 O 2 and H 2 performance. This study provides novel insights into the development of CN‐based photocatalysts that can concurrently generate H 2 and H 2 O 2 .