Evaluation of Antimicrobial and Photocatalytic Degradation of Reactive Black Dye Using Fe3O4/rGO Nanocomposite

Abstract

The growing demand for efficient wastewater treatment technologies has intensified research into nanomaterial-based solutions capable of addressing complex environmental contaminants. In this context, the present study evaluates the performance of bare Fe₃O₄ NPs and the composite of reduced graphene oxide–iron oxide (rGO–Fe₃O₄) as advanced functional materials for wastewater purification. The desirable nanomaterials were synthesised using hydrothermal method and comprehensively characterised by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), BET surface analyzer, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy. The average crystallite sizes of prepared Fe₃O₄ and rGO–Fe₃O₄ were determined to be 21.3 nm and 16.9 nm, respectively. This enhancement was confirmed by the superior performance of rGO–Fe₃O₄ in the degradation of reactive black (RB) dye. The optimised experiments demonstrated that 100% degradation of RB dye was attained when the process was carried out with an agitation time of 80 min, an adsorbent dose of 0.1 g, a solution pH of 12 and an initial dye concentration of 10 mg L^–1. Furthermore, the rGO–Fe₃O₄ nanocomposite exhibited significant antibacterial activity against E. coli and S. aureus. These findings demonstrate that rGO–Fe₃O₄ nanocomposites represent a promising multifunctional material for efficient wastewater treatment and microbial disinfection applications.