Recyclable PbFe₁₂O₁₉–rGO Nanocomposite for Efficient Photocatalytic Malachite Green Degradation and Antimicrobial Application

Abstract

Nanocomposites (NCs) that integrate various metal nanoparticles with carbon-based materials have garnered significant attention due to their synergistic physicochemical properties and broad applicability in environmental and biomedical fields. In this context, the present study provides a comprehensive and pioneering evaluation of the photocatalytic efficiency of a cost-effective, reusable nanocomposite comprising lead hexaferrite (LHF) anchored onto reduced graphene oxide (rGO). Comprehensive characterization techniques, including FTIR, XRD, SEM-EDX, HR-TEM, Raman spectroscopy, and TGA, confirmed the successful grafting of LHF particles onto the rGO surface, enhancing the NC's chemical and thermal stability. The synergistic interaction between LHF and rGO significantly improved the NC's malachite green (MG) dye adsorption capacity to 78.1 mg/g, and showed constant efficiency upto four cycles, surpassing the performance of already available metal based nanocomposites. Under sunlight irradiation, the NC demonstrated exceptional photocatalytic activity, achieving 99% degradation of MG dye within 120 minutes, owing to enhanced generation of hydroxyl radicals and photogenerated holes. This performance is attributed to the synergistic effects of rGO and LHF, boosting effective charge separation and photogenerated carrier transfer across the rGO surface. Importantly, ICP-OES analysis confirmed the absence of lead leaching into the treated water, ensuring environmental safety. Beyond its photocatalytic efficiency, the NC exhibited antimicrobial activity against Bacillus subtilis and Candida albicans, indicating its potential as a dual-functional material for wastewater treatment.