Hollow porous organic framework nanotube for efficient photocatalytic H2O2 generation by promoting H2O oxidation

The hydrogen peroxide (H2O2) generation by photocatalytic O2 reduction coupling H2O oxidation is a promising alternative to the traditional anthraquinone method. However, the low mass transfer and weak water oxidation are still the major responsible for the low efficiency of photocatalytic H2O2 production. Herein, we present a porous organic framework (BPTEE-POF) with hollow nanotube structure containing 2,2′-bipyridine active center of H2O oxidation, which was synthesized by template-free Sonogashira cross-coupling reaction of 5,5′-dibromo-2,2′-bipyridine (BP) and 1,1,2,2-tetrakis(4-ethynylphenyl)ethene (TEE). The 2,2′-bipyridine moieties can effectively weaken HO bond and facilitate H2O oxidation to generate O2 and H+, which can be subsequently employed as reactants for non-sacrificial H2O2 production. Meanwhile, the throughout hollow structure of BPTEE-POF is conducive to mass transfer/diffusion of substrate and product by siphoning, which promotes O2 and H2O molecules to contact with catalytic active sites and causes the quick dissociation of H2O2 from active sites, thereby boosting the overall reaction kinetic and efficiency.