The rapid charge separation and adequate surface-active sites are key points for photocatalytic H2 and H2O2 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 H2 and H2O2 evolution, and the KOCCN-0.5 demonstrates the optimal photocatalytic performance, achieving H2 and H2O2 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-C3N4 (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 H2O2 and H2 production, respectively. The synergistic interplay between K, O, and cyano groups effectively boosts the photocatalytic H2O2 and H2 performance. This study provides novel insights into the development of CN-based photocatalysts that can concurrently generate H2 and H2O2.
Keywords: K, O codoping; Photocatalysis; cyano group; g‐C3N4; photocatalytic H2 production; photocatalytic H2O2 production.
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