K–N Bridge-Mediated charge separation in hollow g-C3N4 Frameworks: A bifunctional photocatalysts towards efficient H2 and H2O2 production

K atoms are successfully introduced into the interlayers of g-C3N4 frameworks. Taking advantage of the K–N bridge and the hollow structure, enhanced separation of photogenerated electrons and holes is achieved on K10-TCN, which facilitates efficient photocatalytic H2 and H2O2 production. [Display omitted] •K atoms are successfully introduced into the interlayers of g-C3N4 frameworks.•K–N coordination serves as an interlayer bridge between adjacent layers.•The synergistic effect of K–N bridge and hollow structure promotes carrier separation.•K10-TCN exhibits superior activity for producing both H2 and H2O2. The development of bifunctional photocatalysts for enhancing hydrogen (H2) and hydrogen peroxide (H2O2) production from water is essential in addressing environmental and energy issues. However, the practical implementation of photocatalytic technology is still constrained by the inadequate separation of photo-generated charge carriers. Herein, potassium (K) atoms are introduced into the interlayers of graphitic carbon nitride (g-C3N4) with a hollow hexagonal structure (K-TCN) and are coordinated with N atoms in adjacent layers. The presence of K–N coordination serves as a layer bridge, facilitating the separation of charge carriers. The hollow hexagonal structure reduces the distance over which photogenerated electrons migrate to the surface, thereby enhancing the reaction kinetics. Consequently, the optimized K-TCN exhibits a dramatically improved photocatalytic H2 (941.6 μmol g−1h−1 with platinum (Pt) as the cocatalyst) and H2O2 (347.6 μmol g−1h−1) generation as compared to hollow g-C3N4 (TCN) and bulk g-C3N4 nanosheet (CN) without K–N bridge under visible light irradiation. The unique design holds promising potential for developing highly efficient bifunctional photocatalysts towards producing renewable fuels and value-added chemicals.