Pyridine Functionalized β-Ketoenamine-Linked Covalent Organic Framework Nanostructures for H₂O₂ Photosynthesis

Incorporating photoactive and hydrophilic functional groups into covalent organic frameworks (COFs) is deemed to be an efficient strategy to boost their photocatalytic performance for producing H 2 O 2 . Here, we report a highly effective COF-based photocatalyst by integrating the pyridine functional group and the β-ketoenamine linkage. The introduction of the pyridine ring can not only promote the separation and transportation of photogenerated electrons and holes but also act as the active sites for oxygen reduction reaction. Meanwhile, the β-ketoenamine linkage reduces the hydrophobicity of the COFs and facilitates the mass transfer of reactants. Besides, the robust β-ketoenamine linkage endows the COFs with significantly improved stability during the photocatalysis process. Consequently, the cofunctionalized COF nanostructure exhibited a H 2 O 2 production rate of 1615.5 μmol g –1 h –1, 4.0 times and 3.0 times those of counterparts without pyridine ring and β-ketoenamine linkage, respectively. This work contributes a feasible idea to design functional COF nanostructures targeting the photosynthesis of H 2 O 2 via promoting charge/mass transfer and improving stability simultaneously.