Postsynthetic functionalization of water stable zirconium metal organic frameworks for high performance copper removal

Calcium-Based Metal-Organic Framework: Detection and Idiosyncratic Removal of Copper by Nano-Particle Deposition

A novel calcium-based metal-organic framework (CaMOF@LSB) was designed and synthesized, exhibiting dual functionality for both selective detection and removal of Cu2+ ions from aqueous solutions. The framework's stability, including solvent and pH variations, was established with notable thermal resilience. Colorimetric Cu2+ detection (≥5 ppm) with a high capture capacity of 484.2 mg g-1 by CaMOF@LSB places this material among the few that ensure efficient colorimetric detection and high removal capabilities of Cu2+ ions. Batch adsorption experiments revealed pH-dependent behavior and competitive interactions. Langmuir and pseudo-second-order kinetics models aptly described adsorption isotherms and kinetics, respectively. Thermodynamic assessments confirmed spontaneous and endothermic adsorption. Mechanistically, nanoparticle deposition contributes to the Cu2+ uptake. CaMOF@LSB also exhibited one of the best removal behaviour of Cu2+ by means of oxide formation on the surface. Regeneration of CaMOF@LSB was achieved by simple sonication in 0.1 M aqueous NaOH solution. The recyclability was also tested up to 5 cycles, and it exhibited a small decrease in adsorption capacity observed across the cycles. This research presents a promising avenue for addressing heavy metal pollution using metal-organic frameworks, thereby offering potential applications in water purification and environmental pollution monitoring and remediation.

Harnessing the Chemical Functionality of Metal-Organic Frameworks Toward Removal of Aqueous Pollutants

Wastewater treatment has been bestowed with a plethora of materials; among them, metal-organic frameworks (MOFs) are one such kind with exceptional properties. Besides their application in gas adsorption and storage, they are applied in many fields. In orientation toward wastewater treatment, MOFs have been and are being successfully employed to capture a variety of aqueous pollutants, including both organic and inorganic ones. This review sheds light on the postsynthetic modifications (PSMs) performed over MOFs to adsorb and degrade recalcitrant. Modifications performed on the metal nodes and the linkers have been explained with reference to some widely used chemical modifications like alkylation, amination, thiol addition, tandem modifications, and coordinate modifications. The boost in pollutant removal efficacy, reaction rate, adsorption capacity, and selectivity for the modified MOFs is highlighted. The rationale and the robustness of micromotor MOFs, i.e., MOFs with motor activity, and their potential application in the capture of toxic pollutants are also presented for readers. This review also discusses the challenges and future recommendations to be considered in performing PSM over a MOF concerning wastewater treatment.

Metal-porphyrinic framework nanotechnologies in modern agricultural management

Metal-porphyrinic frameworks are an important subclass of metal-organic frameworks (MOFs). These porous materials exhibit a large number of applications for sustainable development and related environmental considerations. Their attractive features include (1) as a free base or metalated with zinc(II) or iron(II or III), they are environmentally benign, and (2) they absorb visible light and are emissive and semi-conducting, making them convenient tools for sensing agrochemicals. But the key feature that makes these nano-sized pristine materials or their composites in many ways superior to most MOFs is their ability to photo-generate reactive oxygen species with visible light, including singlet oxygen. This review describes important issues related to agriculture, including controlled delivery of pesticides and agrochemicals, detection of pesticides and pathogenic metals, elimination of pesticides and toxic metals, and photodynamic antimicrobial activity, and has an important implication for food safety. This comprehensive review presents the progress of the rather rapid developments of these functional and increasingly nano-sized materials and composites in the area of sustainable agriculture.

Titanium lanthanum three oxides decorated magnetic graphene oxide for adsorption of lead ions from aqueous media

The current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate the physical and chemical properties of the produced nanocomposites. The FeGO-TiLa was used to enhance the removal of lead ions from aqueous solution. The FeGO-TiLa nanocomposite exhibited a much higher removal efficiency (93%) for lead ions than pure TiLa nanoparticles (81%) and magnetic graphene oxide (74%). The influence of FeGO-TiLa dosage, contact time, solution pH, solution temperature, and starting quantity on the lead ions was evaluated and adjusted. The investigations demonstrated that a pH 6 with 40 mg adsorbent resulted in >91% removal of lead ions at ambient temperature after 120 min. Isotherm models were used to analyze experimental results, and Langmuir model fitted the data well as compared Freundlich model with a maximum adsorption capacity of 109.89 mg g^-1. Kinetic and studies are performed the lead adsorption over FeGO-TiLa follow pseudo-second-order rate. Langmuir and Free energy suggested the lead ions uptake with FeGO-TiLa was monolayer and physical adsorption mechnaism, respectively. Finally, the FeGO-TiLa nanocompoiste can be used as an alternative adsorbent for water remediation.

Advanced applications of Zr-based MOFs in the removal of water pollutants

The global water pollution is caused by the increase of industrial and agricultural activities, which have produced various toxic pollutants. Pollutants in water generally consist of metal ions, pharmaceuticals and personal care products (PPCPs), oil spills, organic dyes, and other organic pollutants. Amongst the adsorbents that have been developed to deal with pollutants in water, Zr-based metal-organic frameworks (MOFs) have drawn scientists' great attention due to their excellent stability and adjustable functionalization. Herein, the present review article introduces the synthetic methods of functionalized Zr-based MOFs and summarizes their applications in water pollution treatment. It also clarifies the interactions and removal mechanisms between pollutants and Zr-based MOFs. The use of these MOFs with eminent adsorption ability and recycling performance have been discussed in detail. Zr-based MOFs also face some challenges such as high cost, lack of real water environment applications, selective removal of pollutants, and low ability to remove composite pollutants. Future research should focus on addressing these issues. Although there is still a blank of the practical utility of Zr-based MOFs on a commercial scale, the research reported to date clearly shows that they are very promising materials for the water treatment.

Removal of methylene blue from aqueous solution using Mg-Fe, Zn-Fe, Mn-Fe layered double hydroxide

Layered double hydroxides (LDH) with highly flexible and adjustable chemical composition and physical properties have attracted tremendous attention in recent years. A series of LDH with different M (Mg, Zn, Mn)-Fe molar ratios were synthesized by the double titration co-precipitation method. The effect of the factors, including M (Mg, Zn, Mn) : Fe molar ratio, pH, and M-Fe LDH dosage, on the ability of the prepared M-Fe LDH to remove cationic methylene blue (MB) dye from aqueous solution were investigated. Results indicated that the removal efficiency of MB (10 mg/L) was the best at the M (Mg, Zn, Mn): Fe molar ratio of 3:1 by using 2.0 g/L of M-Fe LDH at pH 6.0 under 298.15 K. Mg-Fe LDH had the highest removal performance (71.94 mg/g at 298.15 K) for MB compared to those of the Zn-Fe and Mn-Fe LDH. Zn-Fe LDH with the smallest activation energy resulted in the fastest adsorption rate of MB. The pseudo-second-order model and Langmuir adsorption isotherm were also successfully applied to fit the theory of M-Fe LDH for removal of MB.

Water-resistant HKUST-1 functionalized with polydimethylsiloxane for efficient rubidium ion capture

A thin hydrophobic layer of polydimethylsiloxane (PDMS) was successfully coated onto HKUST-1 by a facile chemical vapor deposition (CVD) approach, which enables excellent Rb(i) capture in water.