Porous Organic Frameworks with Integrative Task-Specific O₂/H₂O Active Sites and Donor–Acceptor Dyads for Photocatalytic H₂O₂ Generation

The photocatalytic generation of hydrogen peroxide (H2O2) through the reduction of oxygen (O2) coupled with the oxidation of water (H2O) represents a green and sustainable alternative to the traditional anthraquinone process, but the ability is inevitably tied to the task-specific active sites and the light-harvesting range. Herein, a porous organic framework (TEADP-POF) containing integrative task-specific catalytic active sites and donor–acceptor dyads structure was prepared through tris(4-ethynylphenyl)amine (TEA) reacting with 2,5-dibromopyridine (DP). The triphenylamine moieties being electron-donating and pyridine moieties being electron-withdrawing, their electron push and pull effect could widen the range of light harvesting and accelerate photoinduced charges’ separation and migration. The carbon atoms next to pyridinic N can adsorb and activate the O2 molecule; meanwhile, the nitrogen atoms of triphenylamine moieties could weaken the H2O molecule by hydrogen bond interactions. These spatially separated task-specific catalytic active sites lead to efficient charge separation for the respective O2 reduction half-reaction and H2O oxidation half-reaction. The TEADP-POF with task-specific O2 and H2O active sites and donor–acceptor dyads structure enables it to maximize photoinduced charge utilization and shows high-efficiency photocatalytic generation of H2O2, of which the initial rate is as high as 2136 μmol g–1 h–1 under visible-light (λ ≥ 400 nm) irradiation with the lack of any additives. This study offers a task-specific functionalized protocol for photocatalytic H2O2 production.