Simple and fast dark degradation of methylene blue and Escherichia Coli bacteria by Fe₃O₄/AC/Ag₂S magnetic nanocomposites

چکیده مقاله

With increasing population growth, industrialization, and climate change, access to clean and safe water is becoming a great challenge in many regions. So, the treatment of water from pollutant dye and Escherichia coli bacteria (E. coli) with nanotechnology has attracted great attention among scientists. In this work, Fe₃O₄/activated carbon (AC)/Ag₂S nanocomposites were fabricated by a hydrothermal approach and applied as a nanocatalyst for the removal of methylene blue dye and E. coli from water and wastewater. The findings indicated that Fe₃O₄/AC/Ag₂S nanocomposites exhibited excellent dark catalyst activity, and methylene blue dyes were completely removed from water within 3 min. The prepared Fe₃O₄/AC/Ag₂S nanocomposites exhibited excellent antibacterial activity for the disinfection of water and wastewater contaminated with E. coli bacteria. The prepared Fe₃O₄/AC/Ag₂S nanocomposites were characterized by BET, FESEM, FT-IR, TEM, VSM, XRD, Raman, EDS, elemental mapping, and Zeta potential analysis. The successful synthesis of Fe₃O₄/AC/Ag₂S nanocomposites was confirmed by XRD, EDS, TEM, FESEM, Raman, and Zeta potential analysis. The VSM results showed Fe₃O₄/AC/Ag₂S nanocomposites had superparamagnetic property with Ms. = 13.27 emu/g. The BET results showed Fe₃O₄/AC/Ag₂S nanocomposites had a large effective surface area at about 168.8 m2/g. The electrochemical properties of Fe₃O₄/AC/Ag₂S nanocomposites were studied by CV, EIS, and ECSA analysis. The electrochemical results demonstrate that the incorporation of Ag₂S enhances the redox response of the system, reduces charge transfer resistance, and results in a significant acceleration of interfacial electron exchange kinetics. Based on the experimental results, Fe₃O₄/AC/Ag₂S nanocomposites had excellent potential to treat water and wastewater from both dyes and E. coli, simultaneously. This study provides a promising perspective for the development of multifunctional nanocomposites. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.