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

Photocatalytic H2O2 production from H2O and O2 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 H2O 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 H2O-oxidation centers of triazinyl and alkynyl moieties are conducive to the consumption of photogenerated holes and inhibit electron–hole pair recombination by efficient H2O-oxidation reactions. Meanwhile, the anthraquinone moieties could serve as O2 reduction centers to accept photogenerated electrons and transfer them to the O2 molecules for the subsequent production of H2O2, thereby boosting the overall reaction kinetics, which in turn improves non-sacrificial H2O2 production. The rational design of AQTT-COP with spatially separated O2 reduction centers and dual H2O-oxidation centers enables maximizing photogenerated electron utilization and exhibits efficient photocatalytic H2O2 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 H2O2 production.