Photocatalytic degradation of amoxicillin in aqueous solutions using rGO/BiFeO3 nanocomposites in the presence of LED light irradiation
Leila Mersa, Abdolmotaleb Seid-Mohammadi, Mohammad Reza Samarghandi, Mohammad Khazaei, Ghorban Asgari
Abstract
In current study, a simple hydrothermal approach was used to synthesis of BiFeO 3 nanocomposites on reduced graphene oxide (rGO/BiFeO 3 ) under visible LED light (Vis LED) for photocatalytic degradation of amoxicillin. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and energy dispersive X-ray (EDX) techniques were applied for characterization of the structural, optical, and surface morphological properties of the synthesized catalysts. The effect of different operating parameters such as pHs (3–9), amoxicillin concentrations (5–30 mg/L), catalyst concentrations (0.5–3 g/L) in different reaction times were investigated. The findings revealed that a 1 g/L rGO/BiFeO 3 nanocomposite with an initial pH of 5 and amoxicillin concentration of 5 mg/L could achieve a removal of 80% after 30 min under visible LED light. TOC and COD analyses were achieved to explore the amoxicillin mineralization rate in optimum conditions. The results indicated that 42.78% and 51.12% of TOC and COD were removed after 60 min contact time, respectively. The results also indicated that as the ionic strength increased, the amoxicillin removal rate slightly declined. The degradation of amoxicillin was pseudo-first-order kinetics. The identification of intermediates and final products led to the conclusion that enhanced degradation of amoxicillin during rGO/BiFeO₃ photocatalysis was achieved through β-lactam ring cleavage, and hydroxylation. Also, rGO/BiFeO 3 catalyst exhibited excellent recyclability and durability.