Synthesis of polyoxometalate-based complexes and photocatalytic degradation of metronidazole

A new complex, [Cu2(1,10-phenanthroline-5,6-dione)3(PMo12O40)]2·3H2O (1), was prepared via solvothermal method. A one-dimensional structure was formed by the bonding of ligand and metal. Then, a two-dimensional layered structure was constructed by hydrogen bonding. The structures were characterized using X-ray powder diffraction, Fourier transform infrared spectroscopy, differential thermal analysis and thermogravimetric analysis, X-ray photoelectron spectroscopy, and ultraviolet–visible diffuse reflectance spectroscopy. The degradation of metronidazole under UV light was studied under varying ionic strength and solution pH conditions. Compared with original conditions, the addition of sodium chloride significantly increased the degradation rate of metronidazole to 80.2%.