Nd(III) and Gd(III) Sorption on Mesoporous Amine-Functionalized Polymer/SiO2 Composite

Abstract

The strong demand for rare-earth elements (REEs) is driven by their wide use in high-tech devices. New processes have to be developed for valorizing low-grade ores or alternative metal sources (such as wastes and spent materials). The present work contributed to the development of new sorbents for the recovery of rare earth ions from aqueous solutions. Functionalized mesoporous silica composite was synthesized by grafting diethylenetriamine onto composite support. The physical and chemical properties of the new sorbent are characterized using BET, TGA, elemental analysis, titration, FTIR, and XPS spectroscopies to identify the reactive groups (amine groups: 3.25 mmol N g−1 and 3.41 by EA and titration, respectively) and their mode of interaction with Nd(III) and Gd(III). The sorption capacity at the optimum pH (i.e., 4) reaches 0.9 mmol Nd g−1 and 1 mmol Gd g−1. Uptake kinetics are modeled by the pseudo-first-order rate equation (equilibrium time: 30–40 min). At pH close to 4–5, the sorbent shows high selectivity for rare-earth elements against alkali-earth elements. This selectivity is confirmed by the efficient recovery of REEs from acidic leachates of gibbsite ore. After elution (using 0.5 M HCl solutions), selective precipitation (using oxalate solutions), and calcination, pure rare earth oxides were obtained. The sorbent shows promising perspective due to its high and fast sorption properties for REEs, good recycling, and high selectivity.

An Eco-Friendly Approach to the Control of Pathogenic Microbes and Anopheles stephensi Malarial Vector Using Magnesium Oxide Nanoparticles (Mg-NPs) Fabricated by Penicillium chrysogenum

“…The chemical compositions are clearly shown when comparing the different profiles of the signals as well as their deconvolutions. The C 1s spectra ( Figure 4 B) shows five splitting peaks for C(C, N, H), C(=N, O), or C-O-C, N-C=O (amide), O-C=O, and O-C-O at 284.07, 285.48, 287.31, and 289.89 eV respectively [ 62 , 66 , 67 ], and this gives good evidence for the carbohydrate produced by the organisms. The O 1s spectra ( Figure 4 C) shows two internal splitting peaks at 530.82 and 532.27 eV, which are assigned for O(N, C, H), O-C=O [ 68 , 69 ], and this supports the data produced by the C 1s deconvolutions.…”

Cetylpyridinium Bromide/Polyvinyl Chloride for Substantially Efficient Capture of Rare Earth Elements from Chloride Solution

“…Hence, the CPB was distributed into PVC to form CPB/PVC because of the electrostatic interaction at the surface (van der Waals forces) due to the presence of C–Cl, imino groups, and most of the peaks in CPB/PVC were shifted 5–10 cm −1 . After REE sorption ( Figure 4 c,d), the vibration bands of PVC or CPB/PVC were reduced and shifted slightly to 3–11 cm −1 , which could be due to the sorption of rare earth ions on the surface sorbents [ 44 ].…”

Facile fabrication of a Z-scheme g-C3N5/Gd-MOF/silver nanocube composite as a new generation visible light active photocatalyst for abatement of persistent toxic pollutants

“…33 The peaks of Gd centered at 143.1 eV and 148.79 eV correspond to the spin-orbit of Gd 4d 5/2 and Gd 4d 3/2 in the +3 oxidation state and indicating the attachment of PTA with Gd ions. [34][35][36] The metallic state of silver was confirmed from the deconvoluted peaks at 368.4 and 374.2 eV of Ag 3d 5/2 and Ag 3d 3/2 respectively. 37 Analysis of various functional groups and their interaction between the individual components during nanocomposite formation was performed using FTIR spectroscopy.…”