3D host-guest material of {Ag(pz)} modified {BW12O40} with supercapacitor, photocatalytic dye degradation and H2O2 sensing performances

The synthesis and properties of inorganic-organic hybrids based on {BW12O40} are still the focus of poly-oxometalates. Here, 3D host-guest material with the molecular formula [Ag5(pz)6(H2O)4][BW12O40] (pz = pyr-azine) (1) was synthesized by the hydrothermal method. The single crystal analysis showed that the compound was composed of a [Ag3(pz)4]3} fragment, a [Ag2(pz)2(H2O)4]2} fragment, and a [BW12O40]5-anion. In the structure, Ag ions are connected into 1D wavy linear bridge chains by pz ligands to form {Ag-pz}n. Twelve Ag ions form a large loop via pz, and each loop forms a supramolecular 2D structure with two {BW12O40} and forms a 3D structure through supramolecular interaction. In the three-electrode system with compound 1 as the active substance and nickel foam as the collector, the specific capacitance is 245.6 F g-1 when the current density is 1 A g-1. Higher than those reported in the literature. Constitute a symmetric two-electrode system, with an energy density of 6.9 Wh kg-1, with a power density of 498.7 W kg-1. And after 5000 cycles, the specific capacitance remains at 92.5%. Besides, the photocatalytic degradation rates of methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) were 93.2% and 90.0%, and 93.7%, respectively. Good sensing performance for H2O2, with a wide linear range (5 mu M-0.27 mM) and low detection limit (2.2 mu M).