Metal sulfide ion exchangers: superior sorbents for the capture of toxic and nuclear waste-related metal ions

Fast and Selective Removal of Aqueous Uranium by a K+-Activated Robust Zeolitic Sulfide with Wide pH Resistance

For the nuclear industry, uranium is not only an important strategic resource but also a serious global contaminant with radiotoxicity and high chemotoxicity. It is very important to efficiently capture uranium from complex aqueous solutions for further treatment and disposal of nuclear wastes. Herein, we first demonstrate the suitability of a three-dimensional (3D) water-stable K⁺-exchanged zeolitic sulfide, namely K@GaSnS-1, for the remediation of radioactive and toxic uranium by ion exchange. In comparison to the pristine compound GaSnS-1, the K⁺-activated porous sulfide K@GaSnS-1 exhibits faster [UO₂]²⁺ ion uptake kinetics, following the pseudo-second-order adsorption model. Further studies indicate that K@GaSnS-1 shows high exchange capacity (q_m^U = 147.6 mg/g) and wide pH resistance (pH 2.75-10.87). In particular, it can efficiently capture [UO₂]²⁺ ion even when excessive amounts of Na⁺, K⁺, Mg²⁺, and Ca²⁺ ions are present. The highest distribution coefficient value K_d, signifying the affinity and selectivity for [UO₂]²⁺ ion, reaches as high as 1.24 × 10⁴ mL/g. More importantly, the uranium in corresponding exchanged samples can be facilely and effectively eluted by a low-cost and eco-friendly method. These merits of K@GaSnS-1 make it promising for the effective and selective removal of uranium from complex contaminated water.

Optimizing the removal of strontium and cesium ions from binary solutions on magnetic nano-zeolite using response surface methodology (RSM) and artificial neural network (ANN)

The feasibility of using magnetic nano-zeolite (MNZ) to remove cesium and strontium from their binary corrosive solutions was investigated by considering the multi-variant/multi-objective nature of the process. RSM (Response Surface Methodology) and ANN (Artificial Neural Network) were used to model and optimize the removal system and assess sensitive parameters that can affect the process reliability. MNZ is characterized by its high surface area and cation exchange capacity and possesses good regeneration behavior for both elements using citric acid. Its stability is comparable to other sorbents in acidic media and the stability increases in alkaline media, where dissolution rate follow first order reaction on heterogeneous sites. MNZ removes both contaminants simultaneously with small tendency toward Cs, where MNZ is suggested for application in pre-treatment of highly contaminated alkaline solutions. The percentage removal, decontamination factors, and separation factors have different dependency on the effluent/process conditions; this dependency is the same for both contaminants. Sorption kinetics is initially controlled by external mass transfer through the boundaries then intra-particle diffusion dominates the reactions. The process sensitivity to pH changes is attributed to changes in structural elements -species distribution at the solid/aqueous interface. Cs⁺ and Sr⁺² are exchanged with Na⁺ and H⁺, regardless the effluent pH value, and with Al and Fe cations at specific pH. Isosteric heat of sorption calculations indicated that the total heat needed to complete the reaction was considerably reduced by operating the process at optimized temperature.

Reaction Kinetics for the Covalent Functionalization of Two-Dimensional MoS2 by Aryl Diazonium Salts

The two-dimensional transition-metal dichalcogenide molybdenum disulfide (MoS₂) has been intensely studied in the past several years due to its exceptional electronic, optical, and chemical properties in a wide range of applications. The chemical functionalization of MoS₂ allows its properties and interfacial interactions to be tuned and controlled. Recently, we reported the direct covalent functionalization of semiconducting MoS₂ with aryl diazonium salts, without the use of harsh initial treatments or phase engineering. In this paper, we confirm and expand the covalent functionalization reaction model by performing a detailed study of the reaction kinetics for monolayer MoS₂ functionalized by 4-nitrobenzene tetrafluoroborate (4-NBD). We find that both the Freundlich and Temkin isotherm models are good descriptors of the reaction due to the energetically inhomogeneous surface of MoS₂ and the indirect adsorbate-adsorbate interactions from previously attached nitrophenyl groups, respectively. The reaction kinetics was then found to be well described using a pseudo-second-order model, showing that the order of this reaction is two. This study supports our previous work and gives us a deeper understanding of the nature of the covalent functionalization of MoS₂.

Ionic liquid cations as methylation agent for extremely weak chalcogenido metalate nucleophiles

Selective in situ methylation of terminal chalcogenide ligands of molecular chalcogenido metalate anions in ionothermal reactions with alkylimidazolium-based ionic liquids yields a series of organo-functionalized chalcogenido metalate compounds. We present the syntheses and crystal structures of (C₄C₁C₁Im)_4+x [Sn₁₀S₁₆O₄(SMe)₄][An] _x (1a-1f), (dmmpH)₆[Mn₄Sn₄Se₁₃(SeMe)₄] (2), and (C _n C₁Im)₆[Hg₆Te₁₀(TeMe)₂] (3a, 3b). The methylation was confirmed by Raman spectroscopy, and the optical absorption properties of the methylated compounds were determined and compared to purely inorganic analogs.

Determination of 89Sr and 90Sr in fresh cow milk and raw urine using crystalline synthetic tunnel manganese oxides and layered metal sulfides

⁸⁹Sr and ⁹⁰Sr are both fission products of high radiotoxicity, which can be released in significant amounts in the event of a nuclear accident. Radiostrontium isotopes will follow calcium all along the food chain and, after ingestion, accumulate in the bones. Therefore, it is imperative to be able to determine ⁸⁹Sr and ⁹⁰Sr in raw milk samples in case of an accidental situation to evaluate the dose given by both radionuclides to the population. Several methods exist for conducting ⁸⁹Sr and ⁹⁰Sr determination. However, most of them use at least one chromatographic step to purify strontium. This, unfortunately, increases the analytical time before the results can be released to the authorities. In addition, they often use liquid scintillation counting to determine the ⁸⁹Sr and ⁹⁰Sr activities, a method which can handle only one sample at a time. Here we propose using synthetic tunnel manganese oxides such as cryptomelane and todorokite and layered metal sulfides to selectively extract strontium from fresh milk and raw urine in a batch sorption method. We found that the method is very quick and yields very pure sources of (radio)-strontium, which can be counted in a proportional counter. Data (counts per minute) from the counter were fitted to a mathematical expression enabling the simultaneous determination of ⁸⁹Sr and ⁹⁰Sr. Because a proportional counter often has several drawers, it is typically possible to measure up to 16 samples at a time. Since cryptomelane is a binding phase easily synthesized in a large quantity, we anticipate that this technique could be an interesting alternative to conventional solid phase extraction chromatography methods.

Deep eutectic solvothermal synthesis of an open framework copper selenidogermanate with pH-resistant Cs+ ion exchange properties

Reported here is the deep eutectic solvothermal synthesis of an open framework copper selenidogermanate [NH₃CH₃]_0.75Cu_1.25GeSe₃ (CuGeSe-1), which shows a pH-resistant Cs⁺ ion exchange performance (q_m = 225.3 mg g⁻¹).

Evaluating Solid Sorbents for Recycling Wash Waters Containing Strontium and Calcium

A system for rapid reduction of radioactive contamination and recycle of contaminated waters is called the Integrated Wash-Aid, Treatment, and Emergency Reuse System (IWATERS). First developed for cesium contaminations, IWATERS prescribes the use of salt and surfactant additives to decontaminate radionuclides from urban surfaces. The water is collected and recycled after passing through reactive filtration beds containing selective sorbents. To adapt the IWATERS for strontium contaminations, potential additives to enhance its decontamination from urban surfaces are identified. One possible additive is calcium (Ca2+). However, its concentration can have a very strong detrimental effect on the ability of selective sorbents to remove strontium from spent wash water. We recognized that studies on off-the-shelf sorbents that include Ca2+ concentrations at relevant levels (greater than millimolar) are absent in the literature. To understand better the effect of Ca2+, we completed a literature review, batch tests, and surface complexation modeling to reveal few sorbent options. Only silico-titanate sorbents exhibited high K d values in the presence of Ca2+, but have significant drawbacks in cost and availability. Given the state of the art, it is imperative that alternatives to alkaline earth ions in the IWATERS be identified to permit in situ recycle of the wash waters.

Functionalized layered double hydroxide with nitrogen and sulfur co-decorated carbondots for highly selective and efficient removal of soft Hg2+ and Ag+ ions

A facile composite was fabricated via direct assembly of nitrogen and sulfur co-decorated carbon dots with abundant oxygen-containing functional groups on the surface of the positively charged layered double hydroxide (N,S-CDs-LDH). The novel N,S-CDs-LDH demonstrates highly selective bindings (M-S) and an extremely efficient removal capacity for soft metal ions such as Ag⁺ and Hg²⁺ ions. N,S-CDs-LDH displayed a selectivity order of Ag⁺> Hg²⁺ >> Cu²⁺ >>> Pb²⁺ > Zn²⁺ > Cd²⁺ for their adsorption. The enormous capacities for Hg²⁺ (625.0 mg g^-1) and Ag⁺ (714.3 mg g^-1) and very high distribution coefficients (K_d) of 9.9 × 10⁶ mL g^-1 (C₀ = 20 mg L^-1) and 2.0 × 10⁷ mL g^-1 (C₀ = 20 mg L^-1) for Hg²⁺ and Ag⁺, respectively, place the N,S-CDs-LDH at the top of LDH based materials known for such removal. The adsorption kinetic curves for Hg²⁺ and Ag⁺ fitted well with the pseudo-second order model. For Hg²⁺ and Ag⁺, an exceptionally rapid capture with removal ∼100% within 80 min was observed (C_ions = 30 mg L^-1 and V/m ratio of 1000). The adsorption isotherms were well described using Langmuir isotherm. The N,S-CDs-LDH was successfully applied to highly efficient removal of Hg²⁺ and Ag⁺ from aqueous solutions.

Removal and Recovery of Heavy Metal Ions by Two-dimensional MoS2 Nanosheets: Performance and Mechanisms

We investigated the removal of heavy metals from water by two-dimensional MoS₂ nanosheets suspended in aqueous solution, and restacked as thin film membranes, respectively. From these studies we elucidated a new heavy metal ion removal mechanism that involves a reduction-oxidation (redox) reaction between heavy metal ions and MoS₂ nanosheets. Ag⁺ was used as a model species and MoS₂ nanosheets were prepared via chemical exfoliation of bulk powder. We found that the Ag⁺ removal capacity of suspended MoS₂ nanosheets was as high as ∼4000 mg/g and adsorption accounted for less than 20% of removal, suggesting the reduction of Ag⁺ to metallic silver as a dominant removal mechanism. Furthermore, we demonstrated that MoS₂ membranes were able to retain a similar high removal capacity, and attribute this capability to the formation of a conductive, permeable multilayer MoS₂ structure, which enables a corrosion-type reaction involving electron transfer from a MoS₂ site inside the membrane (anode) to another site on membrane surface (cathode) where heavy metal ions are reduced to metallic particles. The membrane surface remains active to efficiently recover metallic particles, because the primary oxidation products are soluble, nontoxic molybdate and sulfur species, which do not form an insulating oxide layer to passivate the membrane surface. Therefore, MoS₂ membranes can be used effectively to remove and recover precious heavy metals from wastewater.

[Hg4 Te8 (Te2 )4 ]8- : A Heavy Metal Porphyrinoid Embedded in a Lamellar Structure

The use of ionic liquids (C_n C₁ Im)[BF₄ ] with long alkyl chains (n=10, 12) in the ionothermal treatment of Na₂ [HgTe₂ ] led to lamellar crystal structures with molecular macrocyclic anions [Hg₈ Te₁₆ ]^8- (1), the heaviest known topological relative of porphyrin. [Hg₈ Te₁₆ ]^8- differs from porphyrin by the absence of an electronic π-system, which prevents a "global" aromaticity. Quantum chemical studies reveal instead small ring currents in the pyrrole-type five-membered rings that indicate weak local (σ) aromaticity. As a result of their lamellar nature, the compounds are promising candidates for the formation of sheets containing chalcogenidometalate anions.

Monodisperse Ultrasmall Manganese-Doped Multimetallic Oxysulfide Nanoparticles as Highly Efficient Oxygen Reduction Electrocatalyst

The highly efficient and cheap non-Pt-based electrocatalysts such as transition-based catalysts prepared via facile methods for oxygen reduction reaction (ORR) are desirable for large-scale practical industry applications in energy conversion and storage systems. Herein, we report a straightforward top-down synthesis of monodisperse ultrasmall manganese-doped multimetallic (ZnGe) oxysulfide nanoparticles (NPs) as an efficient ORR electrocatalyst by simple ultrasonic treatment of the Mn-doped Zn-Ge-S chalcogenidometalate crystal precursors in H₂O/EtOH for only 1 h at room temperature. Thus obtained ultrasmall monodisperse Mn-doped oxysulfide NPs with ultralow Mn loading level (3.92 wt %) not only exhibit comparable onset and half-wave potential (0.92 and 0.86 V vs reversible hydrogen electrode, respectively) to the commercial 20 wt % Pt/C but also exceptionally high metal mass activity (189 mA/mg at 0.8 V) and good methanol tolerance. A combination of transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical analysis demonstrated that the homogenous distribution of a large amount of Mn(III) on the surface of NPs mainly accounts for the high ORR activity. We believe that this simple synthesis of Mn-doped multimetallic (ZnGe) oxysulfide NPs derived from chalcogenidometalates will open a new route to explore the utilization of discrete-cluster-based chalcogenidometalates as novel non-Pt electrocatalysts for energy applications and provide a facile way to realize the effective reduction of the amount of catalyst while keeping desired catalytic performances.

Metal-organic framework-based materials: superior adsorbents for the capture of toxic and radioactive metal ions

Highly efficient removal of metal ion pollutants, such as toxic and nuclear waste-related metal ions, remains a serious task from the biological and environmental standpoint because of their harmful effects on human health and the environment. Recently, highly porous metal-organic frameworks (MOFs), with excellent chemical stability and abundant functional groups, have represented a new addition to the area of capturing various types of hazardous metal ion pollutants. This review focuses on recent progress in reported MOFs and MOF-based composites as superior adsorbents for the efficient removal of toxic and nuclear waste-related metal ions. Aspects related to the interaction mechanisms between metal ions and MOF-based materials are systematically summarized, including macroscopic batch experiments, microscopic spectroscopy analysis, and theoretical calculations. The adsorption properties of various MOF-based materials are assessed and compared with those of other widely used adsorbents. Finally, we propose our personal insights into future research opportunities and challenges in the hope of stimulating more researchers to engage in this new field of MOF-based materials for environmental pollution management.

[CH3 NH3 ]4 Ga4 SbS9 S0.28 O0.72 H: A Three-Dimensionally Open-Framework Heterometallic Chalcogenidoantimonate Exhibiting Ni2+ Ion-Exchange Property

An open-framework chalcogenidoantimonate, namely, [CH₃ NH₃ ]₄ Ga₄ SbS₉ S_0.28 O_0.72 H (1), has been solvothermally synthesized and structurally characterized. Interestingly, 1 showed Ni²⁺ ion-exchange properties and wide pH resistance, with a maximum exchange capacity of 76.9 mg g^-1 . To the best of our knowledge, this is the first example of amine-directed three-dimensional (3D) heterometallic chalcogenidometalates for highly selective Ni²⁺ ion capture with a high distribution coefficient (K_d =1.65×10⁵  mL g^-1 ).

A hybrid monolithic column based on layered double hydroxide-alginate hydrogel for selective solid phase extraction of lead ions in food and water samples

In order to develop an accurate and precise determination method based on solid phase extraction of Pb(II) in food and water samples, a hybrid monolithic column based on layered double hydroxides (LDHs) nanosheets-alginate hydrogel has been synthesized. Combining the advantages of porous 3D framework of hydrogel with selective adsorption of LDHs toward Pb(II), the hydrogel-based hybrid monolithic column shows enhanced enrichment selectivity and efficiency for target ions. Effects of hydrogel composition, pH, concentration and type of eluent, sample volume, and interfering ions on the recoveries of the analytes were also investigated. Under the optimal experiment conditions of method, the limit of detection, preconcentration factor and precision as RSD% are found to be 0.39 μg L^-1, 53.7 and 2.65%, respectively. Trace Pb(II) can be quantitatively preconcentrated at pH 6.0 with recoveries >97%. Finally, the method was successfully verified by analyzing spiked Pb²⁺ in water and drinking samples.

Efficient Removal of Polycyclic Aromatic Hydrocarbons, Dyes, and Heavy Metal Ions by a Homopolymer Vesicle

It is an important challenge to effectively remove environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs), dyes, and heavy metal ions at a low cost. Herein, we present a multifunctional homopolymer vesicle self-assembled from a scalable homopolymer, poly(amic acid) (PAA), at room temperature. The vesicle can efficiently eliminate PAHs, cationic dyes, and heavy metal ions from water based on π-π stacking, hydrophobic effect, and electrostatic interactions with the pollutants. The residual concentrations of PAHs, cationic dyes, and heavy metal ions (such as Ni²⁺) in water are lower than 0.60 and 0.30 parts per billion (ppb) and 0.095 parts per million (ppm), respectively, representing a promising adsorbent for water remediation. Furthermore, precious metal ions such as Ag⁺ can be recovered into silver nanoparticles by in situ reduction on the membrane of PAA vesicles to form a silver nanoparticle/vesicle composite (Ag@vesicle) that can effectively catalyze the reduction of toxic pollutants such as aromatic nitro-compounds and be recycled for more than ten times.

Towards magnetic responsive chalcogenides for efficient separation in water treatment: facile synthesis of magnetically layered chalcogenide Fe3O4/KMS-1 composite adsorbents and their zinc removal application in water

A novel easily separated magnetic chalcogenide based composite, Fe₃O₄/KMS-1, was successfully synthesized under vigorous stirring of a mixture in ethanol solution.

An ingenious one-dimensional zirconium phosphonate with efficient strontium exchange capability and moderate proton conductivity

A new 1-D zirconium phosphonate [(CH₃)₂NH₂]₂[Zr(CH₂(HPO₃)(PO₃))₂] (SZ-5) was synthesized via a solvothermal reaction and its single crystal structure was elucidated.

Synthesis of thorium–ethanolamine nanocomposite by the co-precipitation method and its application for Cr(vi) removal

Studies on the adsorption of Cr(vi) from water by a thorium ethanolamine nanocomposite.

Anion-Responsive Poly(ionic liquid)s Gating Membranes with Tunable Hydrodynamic Permeability

Novel anion-responsive "intelligent" membranes with functional gates are fabricated by filling polyethersulfone microporous membranes with poly(ionic liquid)s (PILs) gels. The wetting properties of the PILs could be controlled by changing their counteranions (CAs), and thus, the filled PILs gel gates in the membrane pores could spontaneously switch from the "closed" state to the "open" one by recognizing the hydrophilic CAs in the environment and vice versa. As a result, the fluxes of the "intelligent" membranes could be tuned from a very low level (0 mL/m²·mmHg for Cl^-, Br^-, and BF₄^-) to a relatively high one (430 mL/m²·mmHg for TFSI). The anion-responsive gating behavior of the PILs filled membranes is fast, reversible, and reproducible. In addition, the "intelligent" membranes are sensitive to contact time and ion concentrations of the hydrophobic CA species. The proposed anion-responsive "intelligent" membranes are highly attractive for ion-recognizable chemical/biomedical separations and purifications.

Rapid Simultaneous Removal of Toxic Anions [HSeO3]-, [SeO3]2-, and [SeO4]2-, and Metals Hg2+, Cu2+, and Cd2+ by MoS42- Intercalated Layered Double Hydroxide

We demonstrate fast, highly efficient concurrent removal of toxic oxoanions of Se(VI) (SeO₄^2-) and Se(IV) (SeO₃^2-/HSeO₃^-) and heavy metal ions of Hg²⁺, Cu²⁺, and Cd²⁺ by the MoS₄^2- intercalated Mg/Al layered double hydroxide (MgAl-MoS₄-LDH, abbr. MoS₄-LDH). Using the MoS₄-LDH as a sorbent, we observe that the presence of Hg²⁺ ions greatly promotes the capture of SeO₄^2-, while the three metal ions (Hg²⁺, Cu²⁺, Cd²⁺) enable a remarkable improvement in the removal of SeO₃^2-/HSeO₃^-. For the pair Se(VI)+Hg²⁺, the MoS₄-LDH exhibits outstanding removal rates (>99.9%) for both Hg²⁺ and Se(VI), compared to 81% removal for SeO₄^2- alone. For individual SeO₃^2- (without metal ions), 99.1% Se(IV) removal is achieved, while ≥99.9% removals are reached in the presence of Hg²⁺, Cu²⁺, and Cd²⁺. Simultaneously, the removal rates for these metal ions are also >99.9%, and nearly all concentrations of the elements can be reduced to <10 ppb, a limit acceptable for drinking water. The maximum sorption capacities for individual Se(VI) and Se(IV) are 85 and 294 mg/g, respectively. The 294 mg/g capacity for Se(IV) reaches a record value, placing the MoS₄-LDH among the highest-capacity selenite adsorbing materials described to date. More interestingly, the presence of metal ions extremely accelerates the capture of the selenium oxoanions because of the reactions of the metal ions with the interlayer MoS₄^2- anions. The sorptions of Se(VI)+Hg and Se(IV)+M (M = Hg²⁺, Cu²⁺, Cd²⁺) are exceptionally rapid, showing >99.5% removals for Hg²⁺ within 1 min and ∼99.0% removal for Se(VI) within 30 min, as well as >99.5% removals for pairs Cu²⁺ and Se(IV) within 10 min, and Cd²⁺ and Se(IV) within 30 min. During the sorption of SeO₃^2-/HSeO₃^-, reduction of Se(IV) occurs to Se⁰ caused by the S^2- sites in MoS₄^2-. Sorption kinetics for the oxoanions follows a pseudo-second-order model consistent with chemisorption. The intercalated material of MoS₄-LDH is very promising as a highly effective filter for decontamination of water with toxic Se(IV)/Se(VI) oxoanions along with heavy metals such as Hg²⁺, Cd²⁺, and Cu²⁺.

Mercouri G. Kanatzidis: Excellence and Innovations in Inorganic and Solid-State Chemistry

Over the last 3-4 decades, solid-state chemistry has emerged as the forefront of materials design and development. The field has revolutionized into a multidisciplinary subject and matured with a scope of new synthetic strategies, new challenges, and opportunities. Understanding the structure is very crucial in the design of appropriate materials for desired applications. Professor Mercouri G. Kanatzidis has encountered both challenges and opportunities during the course of the discovery of many novel materials. Throughout his scientific career, Mercouri and his group discovered several inorganic compounds and pioneered structure-property relationships. We, a few Ph.D. and postdoctoral students, celebrate his 60th birthday by providing a Viewpoint summarizing his contributions to inorganic solid-state chemistry. The topics discussed here are of significant interest to various scientific communities ranging from condensed matter to green energy production.

Light absorption engineering of a hybrid (Sn3S72-)n based semiconductor - from violet to red light absorption

The crystalline two-dimensional thiostannate Sn₃S₇(trenH)₂ [tren = tris(2-aminoethyl)amine] consists of negatively charged (Sn₃S₇²⁻)_n polymeric sheets with trenH⁺ molecular species embedded in-between. The semiconducting compound is a violet light absorber with a band gap of 3.0 eV. In this study the compound was synthesized and functionalized by introducing the cationic dyes Methylene Blue (MB) or Safranin T (ST) into the crystal structure by ion exchange. Dye capacities up to approximately 45 mg/g were obtained, leading to major changes of the light absorption properties of the dye stained material. Light absorption was observed in the entire visible light region from red to violet, the red light absorption becoming more substantial with increasing dye content. The ion exchange reaction was followed in detail by variation of solvent, temperature and dye concentration. Time-resolved studies show that the ion exchange follows pseudo-second order kinetics and a Langmuir adsorption mechanism. The pristine and dye stained compounds were characterized by powder X-ray diffraction and scanning electron microscopy revealing that the honeycomb hexagonal pore structure of the host material was maintained by performing the ion exchange in the polar organic solvent acetonitrile, while reactions in water caused a break-down of the long-range ordered structure.

Preparation of an ion imprinted functionalized mesoporous silica for rapid and specific absorption Cr(iii) ions in effluents

We developed an effective and selective method to remove Cr(iii) ions in acidic effluents.

Metal–organic frameworks for radionuclide sequestration from aqueous solution: a brief overview and outlook

¹³⁷Cs, ⁹⁰Sr, ²³⁸U, ⁷⁹Se, and ⁹⁹Tc sequestrations from aqueous solution by metal–organic framework materials are summarized in this Frontier article.

Preparation of magnetic porous NiFe2O4/SiO2 composite xerogels for potential application in adsorption of Ce(iv) ions from aqueous solution

In this work, a novel magnetic porous adsorbent was prepared via a sol–gel method for the removal of Ce(iv) from aqueous solution.

Cu2+ sorption from aqueous media by a recyclable Ca2+ framework

A recyclable Ca-MOF that exchanges Ca²⁺ by Cu²⁺ almost quantitatively and quickly was investigated via batch ion-exchange experiments and utilized as a stationary phase in an ion-exchange column for Cu²⁺ removal from aqueous media.