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.