A facile in situ integration of red mud-derived metal oxides into graphene sheets for sulfamethoxazole removal from water

Abstract

In this study, we present a facile in situ integration of red mud-derived metal oxides into graphene sheets via an electrochemical method, and we demonstrate its application for sonodegradation of sulfamethoxazole (SMX) in water. The resulting red mud-derived metal oxides/graphene composite (RAG) has a porous structure (with a specific surface area of 42.08 m² g⁻¹) and contains metal oxides (e.g., TiO₂, Al₂O₃, and Fe₂O₃) and SiO₂ anchored on the surface of the exfoliated graphite flakes via oxygen bridges (e.g., C–O–Ti/Al/Fe). The produced nanocomposites contained Fe²⁺ and Fe³⁺ with a vital role in sonochemical degradation and the oxygen-containing groups such as COOH, C–O–C, and CO for attracting the pollutant molecules to the catalyst surface. The investigated results of SMX degradation indicated an excellent performance of the synthesized RAGs with the highest SMX degradation efficiency of 91.5% at pH 7, SMX initial concentration of 10 mg L⁻¹, catalyst dosage of 0.5 g L⁻¹, volume of 100 mL, temperature of 313 K, and reaction time of 180 min. Besides, the SMX degradation can occur at a wide pH range of 3–7, suggesting a potential solution for removing antibiotic pollutants in environmental remediation.