A new two-fold interpenetrating metal-organic framework based on polyoxometalate: Synthesis, structure, efficient hydrogen evolution and dye degradation

A new POMs-based metal–organic framework (POMOF) with interpenetrated 2-fold architecture compound: [(Ni3(bpp)3·(H2O)11(PW9ⅥW3ⅤO40)]·2H2O (1) (bpp = 3, 5′-bis(pyrid-4-yl)pyridine) has been synthesized under hydrothermally method by introducing a pyridyl-containing rigid ligand into polyoxometalate (POMs) system. In compound 1, the Ni ions simultaneously coordinate with N-donor linker bpp and O-donor linker POM to form 3D frameworks with a large stacking channel. and the 3D frameworks further interpenetrate into each other to form a 2-fold POMOFs architecture. Moreover,the as-obtained POMOF with narrow band (2.07eV) facilitates electron transfer and porous structure for mass transfer. Compound 1 had a high photocatalytic degradation activity of RhB dye with a degradation rate of 90%. At the same time, the as-prepared compound produced excellent catalytic activity and high stability for hydrogen evolution reaction (HER), which manifest an overpotential only 74.6 mV for HER (10 mA cm−2) and Tafel slope of 111 mV dec−1 in 1 M KOH. Our research provides that the as-prepared catalyst possesses bifunctional catalytic performance for both HER and dye degradation.