Polymorphism in Covalent Organic Frameworks Regulates Excited Dynamics for H₂O₂ Photosynthesis Coupled With Biomass...

Polymorphism in covalent organic frameworks (COFs) offers a unique platform to decipher structure-property relationships, yet its impact on excited-state dynamics remains unexplored. Herein, we construct two chemically identical but topologically distinct 1D and 2D COF polymorphs to correlate framework architecture with photocatalytic performance. Impressively, in H₂O₂ photosynthesis coupled with furfuryl alcohol valorization, the 1D-TBPP-COF showed an exceptional H₂O₂ generation rate (18.75 mmol g^-1 h^-1) and selective oxidation of furfuryl alcohol to high-value 6-hydroxy-2H-pyran-3(6H)-one (PN) with PN formation rate of 28.14 mmol·g^-1·h^-1, substantially outperforming the 2D-TBPP-COF counterpart. Mechanistic investigations revealed that the intercalated dual-chain edges in 1D-TBPP-COF impose steric constraints on aromatic ring rotation, effectively suppressing vibrational relaxation losses and prolonging the charge-transfer state lifetime. In contrast, the conformationally flexible 2D-TBPP-COF permits greater rotational freedom, leading to non-radiative energy dissipation. This work establishes polymorphism engineering as a powerful strategy to manipulate excited-state dynamics in COFs for photocatalysis.