Visible Light Response Photocatalytic Performance of Z-Scheme Ag3PO4/GO/UiO-66-NH2 Photocatalysts for the Levofloxacin Hydrochloride.

A Ag3PO4/GO/UiO-66-NH2(AGU) composite photocatalyst was prepared by an ultrasonic-assisted in situ precipitation method. The optical property, structure, composition, and morphology of photocatalysts were investigated using UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy, and charge flow tracking by photodeposition of Pt and PbO2 nanoparticles. In comparison with Ag3PO4 and Ag3PO4/UiO-66-NH2(AU), the AGU composite photocatalyst showed heightened photocatalytic performance for the degradation of levofloxacin hydrochloride (LVF). The AGU photocatalyst (dosage: 0.8 g/L) with 1% mass content of graphene oxide (GO), the mass ratio of Ag3PO4 and UiO-66-NH2(U66N) reached 2:1, showed the highest photodegradation rate of 94.97% for 25 mg/L LVF after 60 min of visible light irradiation at pH = 6. The formation of a heterojunction and the addition of GO synergistically promote faster separation of electron-hole pairs, retain more active substances, and enhance the performance of the photocatalyst. Furthermore, the mechanism of the Z-scheme of the AGU composite photocatalytic is proposed.