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- ISSN: 1573-4110
- E-ISSN: 1875-6727
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UO22+ Ion Capture Enhanced with SiO2-based Compound: Insights into Kinetic, Thermodynamics, and Transport Analysis
- Source: Current Analytical Chemistry, Volume 21, Issue 3, Mar 2025, p. 224 - 243
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- 20 Dec 2023
- 27 Mar 2024
- 06 Jun 2024
Abstract
A new material of SiO2-(1-(bis(2-aminoethyl)amino)-3-(silyl)propane-2-ol) (SiO2-BAEASP) has been successfully synthesized as a promising SiO2-based material for the filtration and capturing UO22+ ions. In this study, the chemical structure and possible uses of SiO2-BAEASP in environmental remediation are explored. Moreover, the methodologies and procedures for synthesizing and characterizing SiO2-BAEASP are also described. In addition, the experimental methodologies regarding the capturing capacity, pH, initial concentrations, and temperature dependence are determined. The FT-IR spectra of SiO2-BAEASP materials show distinct functional groups, including the disappearance of νSi–O–H stretching vibrations and the appearance of sharp νSi–O–Si vibrations. However, detection of the primary and secondary amine stretching frequencies at 3251 cm-1 becomes difficult when it is chelated with UO22+ ions due to its weak density and interference with the –OH stretching frequency. Thermogravimetric analysis (TGA) and weight loss patterns for SiO2-BAEASP before and after capturing UO22+ ions suggest the formation of coordination complexes between UO22+ ions and organic functional groups, impacting the thermal properties of the material. Furthermore, the Powder X-ray Diffraction (PXRD) spectrum indicates that the atomic arrangement within the crystals of the material remains largely unchanged before or after adsorption, suggesting that the adsorption of uranyl ions is likely to occur predominantly on the material's surface, with limited impact on the bulk structure. The SEM shows an increase in surface roughness or the formation of layers of nano-spherical particles on the surface, forming clusters or agglomerations. The maximal capturing capability of UO22+ ions into SiO2-BAEASP is 99% under the experimental circumstances of pH = 5 - 7, i = 50 mg L-1, T = 55°C, dosage = 2 g L-1, and 80 rpm. The capturing of uranyl ions follows the Langmuir isotherm model (R2 ≈ 1) as a favorable process (Rl < 0.02). The capturing process has ΔG = - 8.2083 to -16.0568 kJ mol-1, ΔH (+69.7927 kJ mol−1), and ΔS (+2.616166 kJ mol-1 K-1), which indicates that the adsorption is energy-efficient and spontaneous. The pseudo-second-order and Weber-Morris intraparticle diffusion models (ca. R2 = 1.0) suggest that the capturing mechanism follows chemisorption through three distinct stages of sorption, indicating that intraparticle diffusion primarily governs the transport of UO22+ ions into the SiO2-BAEASP. The main findings confirm the ability of SiO2-BAEASP to trap UO22+ ions in contaminated fluids efficiently and its importance in environmental remediation and resource recovery.
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