A Novel Reduced Graphene Oxide-Attapulgite (RGO-ATP) Supported Fe₂O₃ Catalyst for Heterogeneous Fenton-like Oxidation of Ciprofloxacin: Degradation Mechanism and Pathway

• Main Authors: Ting Zhang, Chunyuan Qian, Pengran Guo, Shuchai Gan, Lingyu Dong, Ge Bai, Qiyang Guo
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Catalysts
• Subjects: graphene; ciprofloxacin; catalytic degradation; hydroxyl oxidation
• Online Access: https://www.mdpi.com/2073-4344/10/2/189

Ciprofloxacin, a third-generation fluoroquinolones (FQs) antibiotic, is observed to increasingly pollute the environment. In this study, a three-dimensional reduced graphene oxide-attapulgite-based catalyst Fe₂O₃/RGO-ATP was prepared and used to analyze the degradation of ciprofloxacin in a heterogeneous Fenton reaction. The heterogeneous catalyst Fe₂O₃/RGO-ATP was prepared by a one-step hydrothermal method, and the samples were characterized using BET(Brunauer-Emmett-Teller) surface area, Raman spectroscopy, X-ray diffraction (XRD), Fourier infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effect of reaction time, temperature, pH, initial concentration, H₂O₂ dosage and reuse time on the degradation of ciprofloxacin by the catalyst Fe₂O₃/RGO-ATP was investigated. The optimum conditions of degradation of ciprofloxacin are observed to be 60 °C, pH 5, H₂O₂ concentration of 2.9724 mmol/L, and initial ciprofloxacin concentration of 50 mg/L. The catalyst could be reused several times with a decline in catalytic capacity. Fourier-transform ion cyclotron resonance mass spectrometer (FT) was also employed to study the degradation products of ciprofloxacin in the aqueous solution. The results show that the heterogeneous catalyst Fe₂O₃/RGO-ATP possessed an excellent ability for the catalytic degradation of ciprofloxacin. Direct hydroxyl oxidation is noted to be the main pathway of degradation of ciprofloxacin, and no defluorination reaction is observed during the degradation process.