A novel magnetite nanorod-decorated Si-Schiff base complex for efficient immobilization of U(vi) and Pb(ii) from water solutions

Abstract

A novel silicon Schiff base complex (Si-SBC) and magnetite nanorod-decorated Si-SBC (M/SiO₂-Si-SBC) were synthesized and well characterized in detail. The synthesized materials were applied for the removal of U(VI) and Pb(II) from water solutions under various experimental conditions. The monolayer maximum adsorption capacities of M/SiO₂-Si-SBC (6.45 × 10⁻⁴ mol g⁻¹ for Pb(II) and 4.82 × 10⁻⁴ mol g⁻¹ for U(VI)) obtained from the Langmuir model at 25 °C and pH = 5.00 ± 0.05 were higher than those of Si-SBC (5.18 × 10⁻⁴ mol g⁻¹ for Pb(II) and 3.70 × 10⁻⁴ mol g⁻¹ for U(VI)). Moreover, DFT calculations showed that the high adsorption energies (E_ad) of 7.61 kcal mol⁻¹ for Pb²⁺-(Si-SBC) and 2.72 kcal mol⁻¹ for UO₂²⁺-(Si-SBC) are mainly attributed to stronger electrostatic interactions. The results revealed that the Si-SBC and M/SiO₂-Si-SBC could be used as efficient adsorbents for the effective elimination of U(VI) and Pb(II) from contaminated wastewater. High sorption capacity and reusability indicated the practical applications of the synthesized materials in environmental pollution cleanup.