The removal of heavy metal ions and microplastics from water remains a significant challenge. This study addresses this issue by introducing mesoporous composites consisting of polyoxometalate-based ionic liquids reinforced on magnetic silica-coated nanoparticles. The composites, Q8 [Mo54] @ SiO2 @ Fe3O4, Q10 [Mo54] @ SiO2 @ Fe3O4, Q8 [Mo46] @ SiO2 @ Fe3O4, and Q10 [Mo46] @ SiO2 @ Fe3O4, are derived from the combination of molybdenum clusters ([Mo46]21- and [Mo54]26-) with tetraoctylammonium and tetradecylammonium counter cations, resulting in ionic liquids Q8 [Mo54], Q10 [Mo54], Q8 [Mo46], and Q10 [Mo46], that are subsequently coated onto SiO2 @ Fe3O4. A comprehensive set of characterization techniques was employed to evaluate the properties of these materials. Fourier transform infrared spectroscopy, UV–vis spectroscopy, thermogravimetric analysis, differential scanning calorimetry, cyclic voltammetry, rheology, elemental analysis, inductively coupled plasma atomic emission spectroscopy, powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering, high resolution transmission electron microscopy, and N2 adsorption-desorption isotherms and gas chromatography-mass spectrometry were utilized. These analyses confirm the composites amorphous surface morphology and large specific surface areas and efficient adsorption properties. Inductively coupled plasma atomic emission spectroscopy results demonstrated remarkable heavy metal ions removal efficiencies, ranging from 79.5 % to 99.3 % in laboratory water and from 92 % to 99 % in industrial wastewater. Additionally, dynamic light scattering analysis showed a 100 % removal efficiency for polyvinyl chloride beads in laboratory water and 95–98 % in industrial wastewater. All composites displays excellent reusability and stability over five cycles.