This review aims to provide an overview regarding the development of luminescent metal–organic frameworks (LMOFs) based sensory materials for the detection of cationic inorganic and organic water pollutants.

Large-scale uranium extraction from seawater (UES) is widely considered as reconciliation to increasing global energy demand and climate change crises. However, an ideal uranium sorbent combining features of high capacity,...

Metal-based oxoanions are potentially toxic pollutants that can cause serious water pollution. Therefore, the segregation of such species has recently received significant research attention. Even though several adsorbents have been employed for effective management of chemicals, their limited microporous nature along with non-monolithic applicability has thwarted their large-scale real-time application. Herein, we developed a unique anion exchangeable hybrid composite aerogel material (IPcomp-6), integrating a stable cationic metal-organic polyhedron with a hierarchically porous metal-organic gel. The composite scavenger demonstrated a highly selective and very fast segregation efficiency for various hazardous oxoanions such as, HAsO 4 2À , SeO 4 2À , ReO 4 À , CrO 4 2À , MnO 4 À , in water, in the presence of 100-fold excess of other coexisting anions. The material was able to selectively eliminate trace HAsO 4 2À even at low concentration to well below the As V limit in drinking water defined by WHO.

The domain of metal-organic frameworks (MOFs) has been the research hotspot to scientific community for last two decades and has witnessed an extraordinary upsurge across various domains in material chemistry....

In recent years, detoxification of contaminated water by different types of materials has received a great deal of attention. However, lack of methodical in-depth understanding of the role of various physical properties of such materials toward improved sorption performance limits their applicable efficiencies. In perspective, decontamination of oxoanion-polluted water by porous materials with different morphologies are unexplored due to a shortfall of proper synthetic strategies. Herein, systematic optimization of sequestration performance toward efficient decontamination of toxic oxoanion-polluted water has been demonstrated by varying the morphologies of an imidazolium-based cationic polymeric network [ionic porous organic polymers (iPOP-5)]. Detailed morphological evolution showed that the chemically stable ionic polymer exhibited several morphologies such as spherical, nanotube, and flakes. Among them, the flakelike material [iPOP-5­(F)] showed ultrafast capture efficiency (up to ∼99 and >85% removal within less than 1 min) with high saturation capacities (301 and 610 mg g–1) toward chromate [Cr­(VI)] and perrhenate [Re­(VII)] oxoanions, respectively, in water. On the other hand, the spherical-shaped polymer [iPOP-5­(S)] exhibited relatively slow removal kinetics (>5 min for complete removal) toward both Cr­(VI) and Re­(VII) oxoanions. Notably, iPOP-5­(F) eliminated Cr­(VI) and Re­(VII) selectively even in the presence of excessive (∼100-fold) competing anions from both high- and low-concentration contaminated water. Further, the compound demonstrated efficient separation of those oxoanions in a wide pH range as well as in various water systems (such as potable, lake, river, sea, and tannery water) with superior regeneration ability. Moreover, as a proof of concept, a column exchange-based water treatment experiment by iPOP-5­(F) has been performed to reduce the concentration of Cr­(VI) and Re­(VII) below the WHO permitted level. Mechanistic investigation suggested that the rare in situ exfoliation of flakes into thin nanosheets helps to achieve ultrafast capture efficiency. In addition, detailed theoretical binding energy calculations were executed in order to understand such rapid, selective binding of chromate and perrhenate oxoanions with iPOP-5­(F) over other nonmetal-based anions.

The role of the organic building units of MOFs towards selective detection of a targeted metal cation (Fe3+) has been demonstrated by systematic screening by varying the number of Lewis basic (pyridyl‐N atoms) sites in a series of isostructural metal–organic frameworks (MOFs). All three fluorescent MOFs are seen to present a quenching response towards Fe3+ ions in water; however, only UiO‐67@N exhibits highly selective and sensitive response, whereas the emission of both UiO‐67 and UiO‐67@NN is quenched by several metal ions. More information can be found in the Research Article by S. K. Ghosh et al. (DOI: 10.1002/chem.202104175).

The potential emergence of fluorescence-based techniques has propelled research towards developing probes that can sense trace metal ions specifically. Although luminescent metal-organic frameworks (MOFs) are well suited for this application, the role of building blocks towards detection is not fully understood. In this work, a systematic screening by varying number of Lewis basic (pyridyl-N atoms) sites is carried out in a series of isostructural, robust UiO-67 MOFs, and targeting a model metal ion-Fe 3 + . All the three fluorescent MOFs are seen to present quenching response towards Fe 3 + ions in water. However, UiO-67@N exhibits highly selective and sensitive response, whereas emission of both UiO-67 and UiO-67@NN is quenched by several metal ions. Detailed experimental and theoretical mechanistic investigation is carried out in addition to demonstration of UiO-67@N being able to sense trace amount of Fe 3 + ions in synthetic biological water sample. Further, UiO-67@N based mixed-matrix membrane (MMM) has been prepared and employed to mimic the real time Fe 3 + ions detection in water.

The excessive use of anthropogenic wastes, such as emerging antibiotics and pesticides, has led to serious water pollution. Therefore, selective identification of those specific types of pollutants in wastewater is of significance owing to their direct detrimental impact upon human health. For practical requirements, a potential sensory material is highly desirable for detection of antibiotics and pesticides in water. As an advanced class of porous materials, porous organic polymers (POPs) are considered a potential candidate for the detection of micropollutants. Herein, we investigated the selective fluorescence quenching mechanism of a highly luminescent, electronically rich chemically stable POP (IP POP -1) toward detection of antibiotics and pesticides in an aqueous medium. IP POP -1 exhibited a selective strong quenching response in the presence of electron-deficient antibiotics (such as nitrofurantoin [NFT] and nitrofurazone [NFZ]) and pesticides like chloropyriphos (CHPS) and nitrofen, among others. IP POP -1 was found to be highly sensitive to NFT and NFZ at trace levels, and the detection limits were found as 0.046 and 0.045 mM, respectively. On the other hand, in the case of the pesticides, CHPS and nitrofen, the detection limits were 0.470 and 0.471 mM, respectively. After the detection test, IP POP -1 could be regenerated for further use without any apparent loss of function. Moreover, detailed mechanism of the detection ability of IP POP -1 were elucidated with the help of a time-resolved photoluminescence lifetime decay study and the density functional theory (DFT). All of these studies suggested that both the fluorescence resonance energy transfer (FRET) and photoinduced electron transfer (PET) processes are responsible behind such selective emission quenching. Furthermore, isothermal titration calorimetry (ITC) experiment was carried out in addition to demonstrate IP POP -1 being able to detect electron-deficient antibiotics in trace amounts in simulated hospital wastewater. Finally, IP POP -1-based mixed-matrix membranes (MMMs) were fabricated and employed to mimic real-time antibiotic detection in water.