Supplementary file 1_Phenolic hydroxyl-functionalized covalent organic frameworks for efficient hydrogen evolution in alkaline media.docx

Its interconnected porous architecture provides a highly conductive scaffold, enhanced electrolyte accessibility, and abundant exposed active sites, thereby facilitating water activation and HER. The resulting COF/DHBT-Cuf electrode delivers efficient HER activity in 1 M KOH, achieving an overpotential of 285 mV at 10 mA cm^-2 with a Tafel slope of 263 mV dec⁻¹. This performance arises from the synergy of nitrogen-rich active sites, phenolic groups, the electron-donating inductive effect of methyl substituents, a high-surface-area microporous channel network, and an extended π-conjugated backbone, collectively promoting charge transport, reactant accessibility, and catalytic kinetics.

This work highlights the potential of the rational design of COFs integrated with three-dimensional conductive architectures as efficient metal-free electrocatalysts for alkaline HER and provides valuable insights into the development of advanced organic framework-based catalysts for sustainable green hydrogen production.</p>