Synthesis, characterization, and photocatalytic activity of Ag3PO4/SBA-15 in ciprofloxacin degradation under polychromatic irradiation

Abstract

Ciprofloxacin (CIP) is a fluoroquinolone antibiotic sensitive to conventional degradation, which allows for the development of greater environmental bacterial resistance. Thus, CIP degradation was evaluated under polychromatic irradiation over silver phosphate and SBA-15 substrates. X-ray diffraction patterns indicated that Ag3PO4 and mesoporous hexagonal SBA-15 showed good crystallinity. The Rietveld refinement was used to index the Ag3PO4 phase. The active vibrational modes related to the characteristic groups of the photocatalysts were identified using Raman spectroscopy and Fourier-transform infrared spectroscopy. Field-emission scanning electron microscopy images revealed that 498-nm cube-like Ag3PO4 particles were predominant. Ultraviolet–visible diffuse reflectance spectroscopy showed that Ag3PO4 and Ag3PO4/SBA-15(20%) showed bandgap energies of 2.25 and 2.14 eV, respectively. Impregnating Ag3PO4 with SBA-15 reduced the specific surface area from 582.1 (for SBA-15) to 373.3 m2 g−1 (for Ag3PO4/SBA-15(20%)). Photocatalytic tests showed that CIP was 78.5% photodegraded using only Ag3PO4 and was 61.96% photodegraded in the presence of Ag3PO4/SBA-15(20%) when irradiated with polychromatic light for 210 min.