High-performance material for the effective removal of uranyl ion from solution: computationally supported experimental studies
Date
2022Metadata
Show full item recordAbstract
Adsorption is a widely used method for pollution
removal and for the recovery of valuable species. In recent years, the
use of metal−organic compounds among the adsorbents used in
adsorption studies has increased. In this study, the performance of
the water-insoluble Fe complex as a metal organic framework
(MOF-Fe-Ta) of water-soluble tannic acid, which is not used as an
adsorbent in uranium recovery and removal, was investigated. For
the characterization of the new synthesized material, Fourier
transform infrared, scanning electron microscopy, and X-ray
diffraction analyses were performed. The changes in the adsorption
process based on various parameters were investigated and
discussed. The point of zero charges value of the adsorbent was
found as 5.52. It was noticed that the adsorption increases as the pH
increases. Analyzing the effect of concentration on adsorption, we determined which model explained the adsorption better. The
monolayer capacity of the adsorbent determined in light of the Langmuir model was reported as 0.347 mol kg−1
. The Freundlich
constant, namely the β value obtained in the Freundlich model, which is a measure of surface heterogeneity, was found to be 0.434,
and the EDR value, which was found from the Dubinin−Raduskevich model and accepted as a measure of adsorption energy, was
10.3 kJ mol−1
. The adsorption was kinetically explained by the pseudo-second-order model and the adsorption rate constant was
reported as 0.15 mol−1 kg min−1
. The effect of temperature on adsorption was studied; it was emphasized that adsorption was energy
consuming, that is, endothermic and ΔH was found as 7.56 kJ mol−1
. The entropy of adsorption was positive as 69.3 J mol−1 K−1
. As
expected, the Gibbs energy of adsorption was negative (−13.1 kJ mol−1 at 25 °C), so adsorption was considered as a spontaneous
process. Additionally, the power and mechanism of the interaction between studied adsorbent and adsorbate are explained through
density functional theory computations. Computationally obtained data supported the experimental studies.
Volume
38Issue
33URI
https://pubs.acs.org/doi/pdf/10.1021/acs.langmuir.2c00978https://hdl.handle.net/20.500.12418/13385