A Novel Ag(I)-Containing Polyoxometalate-Based MOF for Visible-Light-Driven Water Oxidation

A novel 3D Ag(I)-containing polyoxometalate-based MOF of H17[Ag9(AgH8W11O44)2(BPY)9]·2.5H2O (WAg–BPY; BPY = 4,4′-bipyridine) has been solvothermally synthesized, and structurally characterized by elemental analyses, IR spectrum, UV–Vis spectrum, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. WAg–BPY exhibits highly efficient photocatalytic O2 production (964 μmol g−1 in the first 10 min) under visible-light irradiation. More interestingly, transient photocurrent experiments confirm the charge separation and transfer process for the possible mechanism in the photocatalytic reaction. The high photocatalytic efficiency, high stability and good recyclability of the catalyst WAg–BPY demonstrates that Ag(I)-containing polyoxometalate units are crucial factor for water oxidation over heterogeneous systems. The successful synthesis of WAg–BPY not only enriches polyoxometalate-based hybrid materials, but also represents the advantages of the Ag(I)-containing complexes for the potential applications such as heterogeneous photocatalysis and so on.