The mutual modulation of oxygen catalytic sites within an ether-linked covalent organic framework enables efficient photocatalytic oxygen reduction reaction

The establishment of artificial photosynthetic systems for hydrogen peroxide (H 2 O 2 ) synthesis signifies a sustainable and eco-friendly strategy that could replace the conventional anthraquinone oxidation pathway. However, the majority of works have predominantly focused on the modulation of individual catalytic site, while systems that enable mutual regulation between adjacent catalytic sites have received little attention. Herein, we designed two novel ether-linked covalent organic frameworks (TpO-COF and TpOO-COF). Compared with TpO-COF, the cooperative interaction between adjacent oxygen catalytic sites in TpOO-COF results in a synergistic enhancement, yielding superior catalytic efficiency beyond the sum of isolated effects. When using benzoic alcohol as the sacrificial agent, a remarkable H 2 O 2 generation rate of 3067 μmol g −1  h −1 , the TpOO-COF catalyst demonstrates a 7.6-fold increase in activity compared to TpO-COF. According to theoretical analyses, TpOO-COF possesses considerably lower Gibbs free energies for the oxygen intermediates than TpO-COF, confirming the presence of mutual electronic modulation among its oxygen catalytic sites. This work advances a distinctive strategy for modulating catalytic sites while providing valuable mechanistic insights into the structure–activity interplay underlying H 2 O 2 formation.