Synergistic O-Containing Triazine and Imidazole Linker in Covalent Organic Frameworks for Electrochemical Hydrogen Evolution

Electrochemical hydrogen evolution systems with water based on covalent organic frameworks (COFs) provide a promising platform for replacing metal catalysts to drive sustainable development. Until now, rational design of the structure of COFs poses a significant challenge because of the largely overlooked individual or synergistic effects of building blocks and linkers in COFs on their electrocatalytic abilities. Herein, a building block-dependent linker integration pattern is illuminated, and the combination of an O-containing triazine building block with phenanthro[9,10-d]imidazole linker successfully yields a COF material, namely, TFPT–PI-COF, which exhibits a distinctive porous structure and high thermal stability. The composite TFPT-PI-COF@NF as the catalyst demonstrates a promising overpotential value of 120 mV for hydrogen evolution reaction (HER) and delivers a current density of 10 mA cm–2 in alkaline media. The collaborative contributions of O-containing triazine and phenanthro[9,10-d]imidazole are experimentally verified, and the computation analysis of the Gibbs free energy further confirms the presence of the abundant and accessible active sites in the porous TFPT-PI-COF for HER. This integrated strategy furnishes a vast foreground for designing and developing other COF-based electrocatalysts.