Abstract: Covalent organic frameworks (COFs) show promise for solar-driven hydrogen peroxide (H₂O₂) photosynthesis, but are limited by inefficient interlayer charge transport. Here, this study leverages non-covalent interactions arising from steric hindrance to gradually replace alternating C atoms in the central aryl ring of a triphenylarene platform with N atoms, thereby designing and synthesizing a series of tetrazine-based COFs (Tz-COF-N_x). The results show that as the number of N atoms in the COFs backbone increases, the dihedral angle between adjacent aromatic rings progressively decreases. The strengthened interlayer π-π interactions shorten the electron migration distance between layers and significantly improve the separation and migration efficiency of photogenerated charge carriers. The interlayer electron transfer numbers follow the trend: Tz-COF-N₃ (0.021 e^-) > Tz-COF-N₂ (0.011 e^-) > Tz-COF-N₁ (0.006 e^-) > Tz-COF-N₀ (0.001 e^-). Consequently, Tz-COF-N₃ achieves a photocatalytic H₂O₂ production rate of 6316.4 μmol g^-1 h^-1 in pure water, which is 5.3 times higher than that of the benzene-tetrazine COF (Tz-COF-N₀). This study provides a feasible strategy for designing efficient COF-based photocatalysts by tuning the spatial configuration to optimize interlayer interactions and promote interlayer charge transport.

Key words: Covalent organic frameworks, Photocatalytic H₂O₂ production, Interlayer electron transfer, Dihedral angle