Design, Synthesis,\nand Characterization of Polyoxotungstate-Decorated\nIonic Liquid–Based Hybrid Material, [BmIm]<sub>4</sub>[SiW<sub>12</sub>O<sub>40</sub>] toward Rapid Adsorption of Dye and Antibacterial\nActiv

A multifunctional polyoxometalate-ionic liquid (POM-IL)–based\nhybrid material comprising silicotungstic acid, [BmIm]<sub>4</sub>[SiW<sub>12</sub>O<sub>40</sub>], has been synthesized and demonstrated\nits efficiency toward methylene blue removal and as an antibacterial\nagent. Single-crystal XRD analysis confirms that the material crystallizes\nin monoclinic symmetry (SG: <i>Pn</i>), with lattice parameters <i>a</i> = 13.1396(5) Å, <i>b</i> = 16.9655(8) Å, <i>c</i> = 14.3493(7) Å, and <i>Z</i> = 2. The structure\ncomprises a single polyanionic [SiW<sub>12</sub>O<sub>40</sub>]<sup>4–</sup> moiety surrounded by four cationic [BmIm]<sup>+</sup> units of two different conformations, which supported DFT and Hirshfeld\nsurface analysis. The material shows excellent removal efficiency\nfor methylene blue, with a maximum adsorption capacity of 92.47 mg/g\nand 83.05% reusability after five cycles. On the contrary, FTIR and\nζ–potential analyses confirm that electrostatic interactions\nare the predominant factors governing the adsorption process. The\nmaterial also acts as a superior antibacterial agent against the opportunistic\npathogens Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia\ncoli with a MIC of 500–700 μg/mL. However,\na comparative assessment showed that the material was more effective\nagainst P. aeruginosa compared to the\nother two pathogens. PXRD analysis confirms the phase purity, and\nFESEM and TEM analyses exhibit block-shaped morphology with particle\nsizes ∼2–3 μm.