Ultrasound-assisted preparation of LaFeO3/polystyrene for efficient photo-Fenton degradation of ciprofloxacin hydrochloride

Abstract

LaFeO3/polystyrene (LFO/PS) was successfully prepared by depositing perovskite-type LaFeO3 particles on polystyrene using ultrasound-assisted sol-gel and hydrothermal methods. The structure and properties of LFO/PS were also investigated using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), photoluminescence spectra (PL) and other characterization methods. The results showed that the introduction of ultrasound increased the adsorbed oxygen and oxygen vacancy content of LaFeO3. The deposition of LaFeO3 on PS improved the specific surface area of LaFeO3 and solved the problems of easy agglomeration and difficult separation of powdered LaFeO3. The effects of H2O2 concentration, catalyst dosage, solution concentration, pH and inorganic anions on the removal efficiency of ciprofloxacin hydrochloride were also investigated. The removal efficiency of ciprofloxacin hydrochloride by the LaFeO3/polystyrene photo-Fenton system (98.38%) was much higher than that by pure LFO (sonicated, 54.07%) and LFO/PS (unsonicated, 79.88%) photo-Fenton systems under CCIP = 10 mg/L, CH2O2 = 5 mmol/L, dosage = 1.0 g/L, and pH = 9.00. Furthermore, the removal efficiency of total organic carbon (TOC) reached 76.44%. Based on the identification of intermediates by liquid chromatography-mass spectrometry and density functional theory calculations, the main degradation pathways of ciprofloxacin hydrochloride were proposed. This study explores the influence of various factors on oxygen-rich vacancy perovskite/polystyrene in environmental remediation and proposes the advantages of the introduction of ultrasound in catalyst preparation process.