High performance functionalized UiO metal organic frameworks for the efficient and selective adsorption of Pb (II) ions in concentrated multi-ion systems

Morcos, George; Ibrahim, Ahmad; El‐Sayed, Mayyada M. H.; El‐Shall, M. Samy

doi:10.1016/j.jece.2021.105191

Cited by 47 publications

(19 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is further confirmed in previous studies that showed the effect of the increase in the defect number on the increased Pb(II) adsorption in UiO-66 adsorbents . In fact, the UiO-66-0FA sample shows a similar Q max of Pb(II) compared to previously synthesized UiO-66 samples with HCl as a modulator (48.7 mg/g), while it performed much better than a sample synthesized to have as little as 0.1 defects per cluster (19.4–25.5 mg/g) . On the other hand, UiO-66 samples with a higher defect number than that of UiO-66-200FA show higher Pb(II) adsorption capacities that could reach 175.6 mg/g for 2.3 defects per cluster .…”

Section: Resultssupporting

confidence: 87%

Zr-Based Metal–Organic Framework Nanocrystals for Water Remediation

Jrad

Damacet

Yaghi

et al. 2022

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

A series of derivatives of the Zr-based MOF UiO-66 were synthesized, fully characterized, and tested for their efficiency in the adsorption and removal of the highly toxic elements lead (Pb(II)), cadmium (Cd(II)), arsenate As(V), and selenite Se(IV). Different structural engineering techniques were employed to alter the properties of the Zr-MOFs, such as linker functionalization and defect creation to increase the density of adsorption sites. The functionalization of the UiO-66-based structures with carboxylate groups increased the removal efficiency of Pb(II) cations by more than 70% and that of Cd(II) cations by more than 60% to reach 125.2 and 69.1 mg/g, respectively. Moreover, the induced cluster defects were found to be the preferred adsorption sites of the anion pollutants. The adsorption of As(V) and Se(IV) by the high-defect UiO-66-200FA was 132.5 and 30.8 mg/g, respectively, which was higher than that of the less defect UiO-66, while almost no adsorption was achieved by UiO-66(COOH)2. Furthermore, a multivariate (MTV-MOF) approach was employed to investigate the effect of the functional groups on the diffusion of the adsorbates within the porous networks. Interestingly, adsorption equilibrium was reached within minutes for the best-performing MOFs, highlighting their potential to be used in practical water treatment applications. Finally, chemical adsorption seemed to be dominant among binding mechanisms for all the pollutants, which were analyzed in detail to determine the characteristics that govern the adsorption efficiency of UiO-66-based adsorbents. The conclusions provided by this comprehensive study help serve as a guideline for future researchers aiming to employ UiO-66-based adsorbents by providing them with a deep understanding of the design strategies required to maximize the performance of this robust MOF.

show abstract

Section: Resultssupporting

confidence: 87%

Zr-Based Metal–Organic Framework Nanocrystals for Water Remediation

Jrad

Damacet

Yaghi

et al. 2022

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

show abstract

“…[67] The need for desolvation may also be exacerbated in the presence of functional groups on the BDC linkers that would lead to even smaller or more crowded apertures. The partial desolvation hypothesis is consistent with the fact that experimental studies indicate using UiO-67 [25] and the presence of defects [26] can lead to increased Pb 2þ adsorption, likely owing to easier diffusion of Pb 2þ through the MOF. Furthermore, partial desolvation in order to pass through apertures in porous materials is a well-documented process, [68,69] and moderate dehydration only has a minor energy cost (see Fig.…”

Section: Resultssupporting

confidence: 82%

“…Based on these results, we propose that the deprotonated m3-OH group may also act as an adsorption site. In fact, in the acidic conditions typically utilised for Pb 2þ adsorption, [24,25] some of m3-OH groups are likely to be deprotonated according to the pK a s determined in previous work (3.15, 4.43, 6.9, and 11). [70] Furthermore, adsorption modes involving coordination by both the OHgroup at the defect site and the m3-Ogroup may lead to even stronger adsorption.…”

Section: Resultsmentioning

confidence: 82%

“…A separate study by Morcos et al found UiO-67 (an analogue of UiO-66 with larger apertures and pores) to have increased adsorption capacity relative to UiO-66, highlighting the importance of pore size as a factor for Pb 2þ adsorption. [25] A relatively unexplored factor affecting adsorption performance is the presence of defects. A recent study using UiO-66-NH 2 found that an increased concentration of defects due to missing linkers connecting the metal oxide nodes led to enhanced Pb 2þ adsorption.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, in another recent study, the defect sites created at the metal oxide nodes by absent linkers were directly functionalised to be capped by thiourea and amidinothiourea groups; these functional groups adsorbed Pb 2þ with a maximum adsorption capacity of 245.8 mg g À1 . [25] Defects spontaneously formed under experimental conditions may also act as adsorption sites. Previous reports suggest that in aqueous conditions, the most common type of defect likely to form consists of a hydroxide and water group capping the undercoordinated Zr atoms.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computational Investigation of Adsorptive Removal of Pb

2021

View full text Add to dashboard Cite

Adsorption using metal-organic frameworks (MOFs) such as UiO-66 has shown great promise in remediating water sources contaminated with toxic heavy metals such as Pb 2þ , but detailed information about the adsorption process remains limited. In this article, we gained mechanistic insights into Pb 2þ adsorption using both functionalised and defective UiO-66 by performing density functional theory calculations using cluster models. Our benchmarked approach led to a computational model of solvated Pb 2þ (a hemidirected Pb(H 2 O) 6 2þ complex) fully consistent with experimental reports. The analysis of Pb 2þ adsorption using functionalised UiO-66 determined that factors such as electrostatic attraction, chelation, and limited constraints on the Pb 2þ coordination geometry lead to enhanced binding affinity. For these reasons, UiO-66-COOwas identified as the most promising functionalised MOF, consistent with experimental literature. We additionally explored a novel aspect of Pb 2þ adsorption by UiO-66: the role of missing linker defects that often characterise this MOF. We found that the defects expected to form in an aqueous environment can act as excellent adsorption sites for Pb 2þ and the preferred adsorption geometry is again determined by electrostatic attraction, chelation, and constraints on the Pb 2þ coordination geometry. Overall, we conclude that functional groups and defect sites can both contribute to Pb 2þ adsorption and our study provides crucial design principles for improving the UiO-66 MOF performance in toxic Pb 2þ removal from water.

show abstract

Effective adsorption of Pb(II) ion from aqueous solution onto ZSM-5 zeolite synthesized from Vietnamese bentonite clay

Nguyen,

Dinh

et al. 2023

Environ Monit Assess

View full text Add to dashboard Cite

High performance functionalized UiO metal organic frameworks for the efficient and selective adsorption of Pb (II) ions in concentrated multi-ion systems

Cited by 47 publications

References 65 publications

Zr-Based Metal–Organic Framework Nanocrystals for Water Remediation

Zr-Based Metal–Organic Framework Nanocrystals for Water Remediation

Computational Investigation of Adsorptive Removal of Pb

Effective adsorption of Pb(II) ion from aqueous solution onto ZSM-5 zeolite synthesized from Vietnamese bentonite clay

Contact Info

Product

Resources

About