Ag-loaded BiFeO₃/rGO heterostructured photocatalyst for efficient removal of antibiotic micropollutants: Experimental and DFT studies

A facile green hydrothermal method was used to synthesize an Ag-loaded BiFeO₃/rGO (ABR) composite. The characterization analysis has confirmed an enhanced surface area, reduced band gap, and suppressed electron-hole recombination relative to pristine BiFeO₃. The ABR photocatalyst has demonstrated superior degradation of pharmaceutical pollutants ofloxacin (OFL) and norfloxacin (NOR) under visible light, achieving 88.8 % (pH 2, k = 0.0159 min −1 ) and 91.5 % (pH 7, k = 0.0119 min −1 ) removal within 120 min, approximately six times higher than BiFeO₃ and BiFeO₃/rGO. The enhanced activity is due to the modified band structure and efficient charge transfer facilitated by Ag incorporation and chemical coupling between BiFeO₃ and rGO. Density functional theory (DFT) analysis, including HOMO–LUMO, electrostatic potential mapping, and Fukui function indices were used to identify reactive sites and proposed degradation pathways. This integrated experimental and theoretical study highlights that the ABR as an effective and reusable photocatalyst for antibiotic micropollutant remediation with mechanistic clarity. • Ag/BiFeO₃–rGO (ABR) composite synthesized via a facile hydrothermal route showed enhanced visible-light photocatalytic activity • The degradation achieving up to 88.8% ofloxacin and 91.54% norfloxacin degradation within 120 min. • Combined experimental and DFT approaches elucidated degradation pathways. • Excellent photocatalyst stability and reusability demonstrated high activity over nine reuse cycles.