A new POM–MOF hybrid microporous material with ultrahigh thermal stability and selective adsorption of organic dyes

Abstract

Using Keggin heteropolyoxometalate H₃PW₁₂O₄₀ as the template, a new host–guest POM–MOF hybrid material formulated as (CH₃NH₂CH₃)[Cu₂(TPB)₂ (PW₁₂O₄₀)]·4DMF·6H₂O (1) has been successfully synthesized under solvothermal conditions. Complex 1 is characteristic of a 3D host framework constructed from Cu⁺ ions and TPB ligands and containing different types of one-dimensional channels. The larger channels along the c axis are occupied by Keggin polyoxoanions as guests, while the narrower ones along the [110] direction are available to accommodate solvent molecules and counter dimethylamine cations. Complex 1 shows ultrahigh thermal stability and permanent porosity. In addition, dye adsorption and photocatalytic properties of 1 have been investigated. The results indicated that complex 1 is not only a good heterogeneous photocatalyst for the degradation of MO⁻, but also selectively captures MB⁺ from binary mixtures of MB⁺/MO⁻, MB⁺/R6G⁺ or MB⁺/RhB⁺.