A novel pectin/cerium (IV) silicomolybdate-based nanocomposite ion exchanger: preparation, characterization, and applications

Hybrid ion exchangers with high ion exchange capacity (IEC), good stability, and good selectivity for heavy metals formed through a polymer material into an inorganic ion exchanger have always attracted the attention of researchers. In this work, a novel nanocomposite ion exchanger made of pectin and cerium (IV) silicomolybdate (CSM) was synthesized by precipitation technique and used for separating heavy metals and eliminating bacterial pollutants from water systems. The structural and morphological investigation of the synthesized pectin–cerium (IV) silicomolybdate (PCSM) was achieved by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) techniques, whereas, its chemical characterization was performed by energy-dispersive X-ray (EDX) spectroscopy. The IEC, and chemical and thermal stability of the composite were also determined to understand the composite material's properties. The IEC of the PCSM and CSM was 2.56 and 1.78 milli equivalents per g, respectively. PCSM exhibited chemical stability against different chemical solutions and was thermally stable at 600 °C and retained 24.21% of its initial IEC. The distribution coefficient (K_d) values of the numerous investigated metallic ions were assessed using different solvents to determine the composite's ion exchange characteristics. The distribution study indicated that PCSM was more selective toward Cr³⁺ ions. In addition, it was found to be effective for the separation of Cr³⁺ ions from binary metal ion mixtures such as Cd²⁺–Cr³⁺, Pb²⁺–Cr³⁺, Ni²⁺–Cr³⁺, and Co²⁺–Cr³⁺. PCSM has also shown antibacterial activity against Gram-negative bacteria Escherichia coli.

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