Efficient Photocatalytic Synthesis of Hydrogen Peroxide Facilitated by Triptycene‐Based 3D Covalent Organic Frameworks

Abstract

Abstract Covalent organic frameworks (COFs) are widely studied for hydrogen peroxide (H₂O₂) photosynthesis, with 3D COFs standing out for their porous structures and chemical stability. However, the difficult preparation of 3D COFs and the low efficiency in separating photo‐generated electrons and holes (e − and h + ) limits the efficient production of H 2 O 2 . In this study, two kinds of [6+3] 3D COFs (XJU‐1, XJU‐2) with significant charge separation, achieving record‐breaking H₂O₂ photocatalysis rates of 34 777 and 11 922 µmol g⁻¹ h⁻¹, respectively. XJU‐1's superior efficiency stems from its larger pores, enhancing material transport and oxygen (O 2 ) activation. Experimental and theoretical studies have demonstrated that triptycene monomers achieve significant charge separation toward triazine via imine bonds. Moreover, the dimer's smaller singlet‐triplet energy gap (∆E S‐T ) and triptycene's orthogonal configuration enhance singlet oxygen ( 1 O 2 ) production, enabling multiple H 2 O 2 generation pathways. Ultimately, through the oxygen reduction reaction (ORR) pathway, rapid generation of H 2 O 2 can be achieved at multiple catalytic sites. XJU‐1 mainly follows a mixed pathway involving 1e − ‐ORR and 2e − ‐ORR, and XJU‐2 primarily follows the 2e − ‐ORR pathway, respectively. These open the door of triptycene‐based 3D COFs applied in continuous, efficient, and stable photosynthesis of H 2 O 2 .