Magnetic MoS2–Fe3O4 nanocomposites for dual-function adsorption and photocatalytic removal of acetamiprid from water

The persistent detection of the neonicotinoid pesticide acetamiprid (ACE) in aquatic environments, driven by its chemical stability and water solubility, necessitates the development of more efficient remediation strategies. In this work, magnetic MoS₂–Fe₃O₄ nanocomposites were synthesized for the combined adsorption and photocatalytic removal of ACE. Two composites with MoS₂: Fe₃O₄ mass ratios of 5:1 (MF-5:1) and 2:1 (MF-2:1) were prepared by solvothermal growth of Fe₃O₄ on pre-synthesized MoS₂ nanosheets and characterized using XRD, FTIR, XPS, SEM, TEM, and electrochemical techniques. MF-5:1 exhibited superior performance, removing 55 % of ACE (10 ppm) after 3 h of UV–VIS irradiation and retaining 40 % efficiency after three reuse cycles. Langmuir isotherm analysis revealed maximum adsorption capacities of 26.1 mg g⁻¹ for MoS₂ and 19.2 mg g⁻¹ for MF-5:1, exceeding values reported for many conventional adsorbents. Although Fe₃O₄ incorporation slightly reduced adsorption capacity, it enabled magnetic separation, facilitating material recovery. Photocurrent and Mott–Schottky analyses confirmed enhanced charge separation and donor density, contributing to improved photocatalytic activity. These findings demonstrate the potential of MoS₂–Fe₃O₄ nanocomposites as multifunctional, magnetically recoverable materials for pesticide removal and provide new insights into surface and charge transport properties relevant to environmental remediation technologies.