Enhancing Zn (II) recovery efficiency: Bi-divalent nickel–cobalt ferrite spinel NiXCo1-xFe2O4 as a Game-changing Adsorbent—an experimental and computational study.

This study presents a comprehensive investigation into Ni X Co 1-x Fe 2 O 4 (x = 0.5) spinel nanoparticles synthesized through a one-pot hydrothermal method using Co(NO 3) 2.6H 2 O and Ni(NO 3) 2.6H 2 O salts. XRD, FTIR, FESEM, and VSM analyses confirmed a cubic structure of Ni X Co 1-x Fe 2 O 4 (x = 0.5) nanoparticles without impurities. These nanoparticles exhibit efficient Zn (II) adsorption characteristics, following Langmuir isotherm and pseudo-second-order kinetics. The maximum adsorption capacity was measured to be 666.67 mg g−1 at pH = 7, with mechanisms involving both electrostatic attraction and cation exchange. Desorption studies indicate more than 75% Zn (II) recovery in an acidic environment (pH = 2) after three cycles. Computational analysis was used to validate the experimental results through Molecular Dynamics simulations, initially focusing on Ni X Co 1-x Fe 2 O 4 (x = 0.5). Further exploration involved variations in x at 0.25 and 0.75 to identify the optimal Ni and Co ratio in this bivalent cation spinel ferrite. Computational analyses reveal the superior performance of Ni X Co 1-x Fe 2 O 4 (x = 0.75) in Zn (II) removal, supported by radial distribution analysis, VdW energy, Coulombic energy, mean square displacement (MSD), root mean square displacement (RMSD), and interaction energy. This comprehensive study provides valuable insights into the adsorption behavior and structural stability of Ni X Co 1-x Fe 2 O 4 nanoparticles, showcasing potential applications in Zn (II) removal. [Display omitted] • One-pot synthesis produced pure Ni₀.₅Co₀.₅Fe₂O₄ spinel nanoparticles with cubic structure and no impurities. • Nanoparticles adsorbed Zn(II) at 666.67 mg/g (pH 7), fitting Langmuir isotherm and pseudo-second-order kinetics. • Molecular Dynamics (MD) simulations found Ni₀.₇₅Co₀.₂₅Fe₂O₄ optimal for Zn(II) removal. • Validated structural stability and performance using experiments and MD simulations, confirmed by various energy parameters. • Ni₀.₇₅Co₀.₂₅Fe₂O₄ nanoparticles show promise for efficient Zn(II) removal in water treatment. [ABSTRACT FROM AUTHOR]