The construction of conjugated organic polymers containing phenanthrenequinone redox centers for visible-light-driven H2O2 production from H2O and O2 without any additives

Photocatalytic preparation of hydrogen peroxide (H2O2) by visible light irradiation is a promising approach to achieve the conversion of solar-to-chemical energy. But it still faces a huge challenge with the development of efficient and environmentally friendly catalytic system which is applied to H2O2 production from H2O and O2 without any additives. Hereby, we present a conjugated organic polymer (PQTEE-COP) by Sonogashira cross-coupling reaction between 2,7-dibromophenanthrenequinone (PQ) with 1,1,2,2-tetrakis(4-ethynylphenyl)ethene (TEE), which contains phenanthrenequinone redox centers and can efficient photocatalysis the production of H2O2 from H2O and O2 without any additives. The extended two-dimensional π-conjugated framework with electron-donor tetrakis(4-ethynylphenyl)ethene and electron-acceptor phenanthrenequinone moieties can not only improve visible light harvesting, but also accelerate photo-induced charges separation and migration. In addition, the phenanthrenequinone moieties can serve as redox centers to accept photo-induced electrons and transfer to adsorbed O2 molecule for subsequent H2O2 production through electron-coupled hydrogenation reaction (PQ to PQH2). The PQTEE-COP exhibits efficient photocatalytic production of H2O2 with initial rate of 3009 μmol g-1 h-1 from H2O and O2 under visible light (λ ≥ 400 nm) irradiation without any additives. This work provides a scheme for the rational design of conjugated organic polymer based materials for efficient solar-to-chemical energy conversion.