Investigation of functionalized magnetite nanoparticles with trioctylamine adsorbent for the removal of iridium (IV) from acidic media

This research entailed the manufacture of TOA (Trioctylamine)-functionalized magnetite nanoparticles by the co-precipitation technique. The crystallographic and chemical properties of the new adsorbent were analyzed using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The magnetic nanoparticles were assessed as a new solid-phase adsorbent for removing Iridium (IV) ions from acid solutions. Batch studies were performed to investigate the influence of initial pH, adsorbent concentration, initial Ir (IV) concentration, and shaking duration on the adsorption efficiency of Ir (IV), as well as the desorption of Ir (IV) and interfering ions. The ideal conditions identified were pH: 1.0, adsorbent dosage: 300 mgL^-1, Ir (IV) concentration: 10 mgL^-1, and contact time: 20 min. The non-linear isotherm and kinetic analyses demonstrated that the Toth model and the model with pseudo-second-order well characterize the adsorption data. The maximum adsorption capacity was determined to be 23.94 mgg^-1. Thermodynamic investigations have shown that the adsorption process of Ir (IV) is spontaneous, endothermic, and proceeds via a mixed mechanism in which physisorption predominates with a chemisorption contribution. The determined activation energy was 55.40 kJmol⁻¹. The maximum Ir (IV) desorption value of 82.0 percent was attained with 1.0 M ammonium acetate as the desorbing agent. According to the current work, magnetite nanoparticles functionalized with TOA may be employed as a possible Ir (IV) adsorbent.