Chemically Stable and Porous Bi 2 S 3 /Mg(OH) 2 Nanocomposite for Highly Efficient Adsorption of Radioactive Iodide

Water contamination by radioactive iodide (I – ) presents significant environmental and public health risks. In this study, a chalcogenide-based hydroxide nanocomposite (Bi 2 S 3 /Mg(OH) 2 ) was developed as an efficient adsorbent for (I – ) removal. FE-SEM analysis revealed that Bi 2 S 3 nanoparticles were uniformly anchored on Mg(OH) 2 polyhedral surfaces, increasing the surface area to 22.154 m 2 /g. XPS confirmed the presence of Bi 3+, S 2–, Mg 2+, and I 3d states after adsorption. EDX analysis showed an even element distribution. The inclusion of Mg(OH) 2 improved the iodide adsorption capacity ( q e ) from 171.27 to 203.61 mg/g at neutral pH. The adsorption process followed pseudo-second-order kinetics, as indicated by the correlation coefficient R 2 ≥ 0.99, with Langmuir maximum capacities ( q max ) of 175.063, 202.584, and 239.786 mg/g for Bi 2 S 3, Mg(OH) 2, and the nanocomposite, respectively. Thermodynamic studies revealed that the adsorption process was spontaneous and exothermic. Reusability tests confirmed a high adsorption efficiency even after five regeneration cycles. The nanocomposite presents a promising adsorbent material for the treatment of iodide-contaminated water.