Two new uranyl complexes as visible light driven photocatalysts for degradation of tetracycline

In this paper, two new uranyl complexes (H 2 -bpp)[(UO 2 )( p -nba) 3 ] 2 1 and (H 2 -bipy)[(UO 2 ) 4 ( μ 3 –O) 2 ( p -nba) 6 ] 2 were synthesized by hydrothermal method base on the reaction of UO 2 Ac 2 ·2H 2 O as the metal sources, p -nitrobenzoic acid (H p -nba), 4,4′-bipyridine (bipy) and 1,3-di(4-pyridyl)-propane (bpp) as the ligands in an aqueous system. Complex 1 exhibits two crystallographically unique uranyl cation of 8-fold coordinated. Complex 2 presents a μ 3 -oxido bridged tetranuclear uranyl structural unit of edge-sharing polyhedral connection mode. These complexes were characterized by elemental analyses, IR spectra, thermogravimetric analyses (TGA), UV−Vis spectra and powder X-ray diffraction (XRD) patterns. The photoluminescence properties were investigated for the two complexes. 1 and 2 exhibit good photocatalytic activities for degradation of tetracycline hydrochloride (TC) under visible light irradiation. Moreover, it is verified that the kinetics of degradation rate was well described by the pseudo-first-order kinetics.