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–organic polyhedra (MOP) are a promising class of crystalline porous materials with multifarious potential applications. Although MOPs and metal–organic frameworks (MOFs) have similar potential in terms of their intrinsic porosities and physicochemical properties, the exploitation of carboxylate MOPs is still rudimentary because of the lack of systematic development addressing their chemical stability. Herein we describe the fabrication of chemically robust carboxylate MOPs via outer‐surface functionalization as an a priori methodology, to stabilize those MOPs system where metal–ligand bond is not so strong. Fine‐tuning of hydrophobic shielding is key to attaining chemical inertness with retention of the framework integrity over a wide range of pH values, in strong acidic conditions, and in oxidizing and reducing media. These results are further corroborated by molecular modelling studies. Owing to the unprecedented transition from instability to a chemically ultra‐stable regime using a rapid ambient‐temperature gram‐scale synthesis (within seconds), a prototype strategy towards chemically stable MOPs is reported.

A triboelectric nanogenerator (TENG) based on natural seeds and electrospun poly­(vinyl difluoride) (PVDF) fibers is reported. The nanofibers are specifically used to enhance the triboelectric effects. A mustard (flax) seed based TENG renders an impressively high electrical output with an average open circuit voltage of 84 V (126 V) and maximum power density 334 mW m–2 (324 mW m–2) under an impact force of 40 N at 25 Hz. Basil seeds are relatively weaker in power delivery. By comparing the seed crust properties and TENG performances, we analyze the powering capability in terms of the cellulose content in the crust, dielectric constant, and surface morphological features.

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.

Thanks to a bottom-up Lego® design of metals and organic ligands, the library of metal-organic frameworks (MOFs) have seen a conspicuous growth. Post-synthetically modified MOFs comprise a relatively smaller subset...

Metal–organic frameworks anchored with metal oxide nanoparticles for the detection of H2S gas with enhanced sensitivity.

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.