Anthraquinone-Based Conjugated Organic Polymers Containing Dual Oxidation Centers for Photocatalytic H₂O₂ Production from H₂O and O₂ under Visible-Light Irradiation

Photocatalytic H 2 O 2 production from H 2 O and O 2 under visible-light irradiation is a promising method for the green chemical industry and the conversion of solar energy to fuel. However, the efficiencies remain relatively low due to the rapid photogenerated charge recombination caused by the inefficient H 2 O oxidation. Herein, we present an anthraquinone-based conjugated organic polymer (AQTT-COP) containing alkynyl and triazinyl dual oxidation centers by the Sonogashira cross-coupling reaction of 2,6-dibromoanthraquinone (AQ) and 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine (TT). The dual H 2 O-oxidation centers of triazinyl and alkynyl moieties are conducive to the consumption of photogenerated holes and inhibit electron–hole pair recombination by efficient H 2 O-oxidation reactions. Meanwhile, the anthraquinone moieties could serve as O 2 reduction centers to accept photogenerated electrons and transfer them to the O 2 molecules for the subsequent production of H 2 O 2, thereby boosting the overall reaction kinetics, which in turn improves non-sacrificial H 2 O 2 production. The rational design of AQTT-COP with spatially separated O 2 reduction centers and dual H 2 O-oxidation centers enables maximizing photogenerated electron utilization and exhibits efficient photocatalytic H 2 O 2 production with an initial rate of 3221 μmol g –1 h –1 under visible-light (λ ≥ 400 nm) irradiation without any additives. This work provides a protocol for the unification of task-specific catalytically active components for photocatalytic H 2 O 2 production.