The MOF+Technique: A Significant Synergic Effect Enables High Performance Chromate Removal

Fabricating Industry-Compatible Olefin-Linked COF Resins for Oxoanion Pollutant Scavenging

Large-scale and low-cost synthesis of covalent organic frameworks (COFs) to meet the demands of industrial application remains formidably challenge. Here we report using 2,4,6-collidine as monomer to produce a series of highly crystalline olefin-linked COFs by a melt polymerization method. This method enables the kilogram-scale fabrication of self-shaped monolithic robust foams. The afforded COFs possess extremely low cost (<50 USD/kg), superior to all the reported COFs. Furthermore, using one-pot or post-modification methods can conveniently transform neutral COFs to ionic COFs, which can be applied as highly efficient ion-exchange sorbents for scavenging oxoanion pollutants. Remarkably, the superior adsorption capacity of a model oxoanion (ReO₄ ^- ) is the highest among crystalline porous materials reported so far. This work not only expands the scopes of olefin-linked COFs but also enlightens the route for the industrial production of crystalline ion exchange sorbents.

Raspberry-Like Gold Nanoparticles Based On Nanoclusters Anchored on Cyclodextrin-Functionalized Nanoparticles: Synthesis and Ultrasensitive Electrochemical Detection of Chromium(VI) Ions

A facile synthetic strategy is devised to construct raspberry like gold nanoparticles (RbNPs) formed by gold nanoclusters wrapped around β-cyclodextrin functionalized gold nanoparticles (CD-AuNPs@AuNCs). An efficient and sensitive electrochemical sensor for the detection of Cr(VI) has been developed based on RbNPs. The sensing platform exhibits an excellent wide linear range (100 pg mL^-1 to 10 μg mL^-1 ), extremely low detection limit (40.91 fg mL^-1 i. e. 0.79 pM), which may pave a new way to fabricate other ultrasensitive electrochemical sensors based on the designed RbNPs.

Imidazolium-Functionalized Chemically Robust Ionic Porous Organic Polymers (iPOPs) toward Toxic Oxo-Pollutants Capture from Water

Fabricating new and efficient materials aimed at containment of water contamination, in particular removing toxic heavy metal based oxo-anions (e. g. CrO₄ ^2- , TcO₄ ^- ) holds paramount importance. In this work, we report two new highly stable imidazolium based ionic porous organic polymers (iPOPs) decorated with multiple interaction sites along with electrostatics driven adsorptive removal of such oxo-anions from water. Both the iPOPs (namely, iPOP-3 and iPOP-4) exhibited rapid sieving kinetics and very high saturation uptake capacity for CrO₄ ^2- anions (170 and 141 mg g^-1 for iPOP-3 and iPOP-4 respectively) and ReO₄ ^- (515.5 and 350.3 mg g^-1 for iPOP-3 and iPOP-4 respectively), where ReO₄ ^- anions being the non-radioactive surrogative counterpart of radioactive TcO₄ ^- ions. Noticeably, both iPOPs showed exceptional selectivity towards CrO₄ ^2- and ReO₄ ^- even in presence of several other concurrent anions such as Br^- , Cl^- , SO₄ ^2- , NO₃ ^- etc. The theoretical binding energy calculations via DFT method further confirmed the preferential interaction sites as well as binding energies of both iPOPs towards CrO₄ ^2- and ReO₄ ^- over all other competing anions which corroborates with the experimental high capacity and selectivity of iPOPs toward such oxo-anions.

Nanoscale zeolitic imidazole framework-90: selective, sensitive and dual-excitation ratiometric fluorescent detection of hazardous Cr(vi) anions in aqueous media

Toxic Cr(vi) anions sensing in aqueous solution has been achieved by virtue of fluorescent nanoscale ZIF-90 and RhB@ZIF-90.