Dendrimer functionalized spinel ferrite for robust sorption of precious metals from strongly acidic medium

• Published in: Solid state sciences 2023-10, Vol.144, p.107301, Article 107301
• Main Authors: Harinath, Y., Kumar, N. Sathish, Seshaiah, K., Katta, Ravinder, Reddy, D. Amaranatha
• Format: Article
• Language: English
• Subjects: Dendrimer grafting; Kinetics; Nanocomposite; Pt(IV) and Pd(II) sorption; Sorption mechanism; Spinel ferrite
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2023.107301

The separation of noble metal ions from strongly acidic solutions is considered to be a challenging task due to the significantly low pH of these solutions. Spinel ferrites possess unique physicochemical properties, such as excellent magnetic properties, high specific surface area, high chemical stability, active surface sites, and easy modification or functionalization, making them suitable for various applications. In this study, we have introduced a facile method for synthesizing polyamidoamine (PAMAM) dendrimer-functionalized spinel ferrite (DFSF) with a particle size of approximately 10 nm. The prepared DFSF materials have investigated its ability to adsorb Pt(IV) and Pd(II) anions (PtCl62− and PdCl42−) from strongly acidic solutions. The results indicate that the adsorption kinetics and isotherm studies of synthesized materials have a rapid and high adsorption capacity for Pt(IV) and Pd(II) with simple solid-liquid separation. The data analysis suggests an anion exchange interaction between the adsorbate and the adsorbent, specifically the electrostatic interaction between the protonated amine group (–NH3+) and the noble metal anions (PtCl62–and PdCl42−). The Pseudo second-order rate model fitting suggests that the adsorption of noble metals by DFSF is a function of valence. The excellent superparamagnetic properties (0.346 emu g−1) of DFSF make it a promising candidate for large-scale applications, as it exhibited good reusability with a short recovery time (25 s) and high recovery efficiency through the adsorption-reduction-precipitation route. This study suggests that DFSF can be a potential sorbent for noble metal ions in various applications. [Display omitted] •New nanocomposite material, CoFe2O4@ PAMAM spinel ferrite (DFSF) with a particle size of ∼10 nm was synthesized.•The prepared sorbent showed fast (5 min) and high adsorption performance [(404 mg/g for Pt(IV) and 523 mg/g for Pd(II)] due to its abundant adsorption sites.•The prepared material can be reused for up to five cycles without significant loss of sorption capacity.•The prepared DFSF nanoparticles can be magnetically separated from aqueous solutions with ease.•New nanocomposite material, CoFe2O4@PAA spinel ferrite (DFSF) with a particle size of ∼10 nm was synthesized.