Construction of two new polyoxometalate complexes and their recyclability in photodegradation of cephalexin and ceftiofur

Two new solid photocatalysts, [Cu(Dione) 2 H 2 O] 2 Cl∙(PMo 12 O 40 ) (1) and [Cu(En) 2 H 2 O] 4 ∙[Cu(En) 2 (PW 12 O 40 )] 2 ∙(PW 12 O 40 ) 2 ·2H 2 O (2), were synthesized by hydrothermal method. Their structures were characterized by X-ray diffraction (XPRD), Fourier transform infrared (FT-IR), thermogravimetry (TG), X-ray photoelectron spectra (XPS), and UV–Vis diffuse reflection spectra (UV–Vis DRS). Their catalytic performances were tested in UV-irradiated solutions of cefalexin and ceftiofur. In complexes 1 and 2, there exist intramolecular hydrogen bonds. A three-dimensional (3D) structure is formed by hydrogen bonding in complex 1. The prepared complexes exhibit definite structures, good thermal stability, and high photocatalytic efficiency, particularly in acidic environments. The degradation rates of ceftiofur in the presence of complex 2 can reach 90.61%. They are also reusable after five rounds of repeated experiments.