Search

The severe water pollution from effluent dyes threatens human health. This study created pH-magnetic-photocatalytic polymer microspheres to conveniently separate the photocatalyst nanoparticles from the treated water by applying an external magnetic field. While fabricating magnetic nanoparticles’ (MNPs) microspheres, incorporating 0.5 wt.% iron oxide (Fe3O4) showed the best magnetophoretic separation ability, as all the MNPs microspheres were attracted toward the external magnet. Subsequently, hybrid organic–inorganic polyoxometalates (HPOM), a self-synthesized photocatalyst, were linked with the functionalized magnetic nanoparticles (f-MNPs) to prepare augmented magnetic-photocatalytic microspheres. The photodegradation dye removal efficiency of the augmented magnetic-photocatalytic microspheres (f-MNPs-HPOM) was then compared with that of the commercial titanium dioxide (TiO2) photocatalyst (f-MNPs-TiO2). Results showed that f-MNPs-HPOM microspheres with 74 ± 0.7% photocatalytic removal efficiency better degraded methylene orange (MO) than f-MNPs-TiO2 (70 ± 0.8%) at an unadjusted pH under UV-light irradiation for 90 min. The excellent performance was mainly attributed to the lower band-gap energy of HPOM (2.65 eV), which required lower energy to be photoactivated under UV light. The f-MNPs-HPOM microspheres demonstrated excellent reusability and stability in the photo-decolorization of MO, as the microspheres retained nearly the same removal percentage throughout the three continuous cycles. The degradation rate was also found to follow the pseudo-first-order kinetics. Furthermore, f-MNPs-HPOM microspheres were pH-responsive in the photodegradation of MO and methylene blue (MB) at pH 3 (acidic) and pH 9 (alkaline). Overall, it was demonstrated that using HPOM photocatalysts in the preparation of magnetic-photocatalytic microspheres resulted in better dye degradation than TiO2 photocatalysts.

A bis‐tryptophan tweezer was installed on a polyoxometalate (POM) surface via a bis‐amide covalent bond, yielding the enantiopure hybrid POM with C2 symmetry, as a result of the regioselective functionalization of decatungosilicate [γ‐SiW10O36]8– at the lacunary site. The combined polyanionic and receptor properties are instrumental for a POM‐driven solubilization and enrichment of single walled carbon nanotubes (SWCNTs) with diameter <1.1 nm, as demonstrated by Raman and UV/Vis‐NIR evidence, in agreement with the calculated energetics of the tryptophan tweezer–SWCNT interaction. The preference of SWCNT(9,3) to interact within a tryptophan‐based hydrophobic pocket is demonstrated by experimental and computational evidence, addressing the selective binding of a polyoxometalate‐based tweezer [ABSTRACT FROM AUTHOR]

Novel organic‐inorganic polyoxometalates (POMs) decorated with covalent fluorescent tags have been designed for cell internalization. Their localization within model HEK cells is readily accomplished by confocal fluorescence microscopy. While cell internalization is dictated by the formation of the amphiphilic POM‐based nanostructures, their cytoplasmic‐nuclear trafficking appears to be regulated by a subtle interplay of the organic‐inorganic domains of the nanoassemblies which, in turn, impacts their dynamic behavior and capability to interact with cell membranes. Polyoxometalates with appended fluorescent tags form nanoparticles that can internalize into cells, with a localization depending on their composition. [ABSTRACT FROM AUTHOR]

In this study, a new organic–inorganic material, based on an alpha-metatungstate [H 2 W 12 O 40 ] 6 − cluster, was synthesized via the hydrothermal method by using aminopyridinium (APy) + cations as the hybrid material, and characterized by FT-IR and UV spectra analysis. The hybrid composite was immobilized on a gold electrode decorated with gold nanoparticles (AuNPs) and the modified electrode exhibited excellent electrocatalytic activities towards the reduction of H 2 O 2 at neutral pH with a response time of < 10 s. The H 2 O 2 response at the modified electrode displays a linear response ranging from 40 μM to 10 mM. Based on the H 2 O 2 reduction activity, the (APy) 6 [H 2 W 12 O 40 ] composite was successfully used for the fabrication of a novel enzymatic glucose biosensor. The glucose oxidase enzyme (GOx) was immobilized onto the hybrid composite on AuNPs/gold electrodes; the (APy) 6 [H 2 W 12 O 40 ] composites were used as both mediation and bridging molecules. A multilayer architecture was constructed from hybrid POM alternating with (GOx), using glutaraldehyde as a covalent attachment cross-linker. Cyclic voltammetry (CV), SWV and chronoamperometry were used to determine the electrochemical properties of the mediator and characterize its reaction with (GOx). The resulting glucose biosensor exhibits a wide linear response for glucose from 40 μM to 10 mM with a sensitivity of 15.0 μA mM − 1 . [ABSTRACT FROM AUTHOR]

The desulfurization efficiency of various hybrid zinc-substituted polyoxometalates ([PW 11 Zn(H 2 O)O 39 ] 5 − , abbreviated as PW 11 Zn) was here investigated for the first time and optimized using sustainable systems conciliating successfully the liquid–liquid extraction and the oxidative catalytic process. Initially, the desulfurization studies were performed using a model diesel containing a mixture of the most refractory sulfur compounds and later extended to an untreated real diesel. In both cases, acetonitrile was used as extraction solvent and aqueous H 2 O 2 as oxidant. High level of desulfurization was achieved using model and untreated diesels after few hours. The quaternary ammonium catalysts (TBAPW 11 Zn and ODAPW 11 Zn) showed higher catalytic desulfurization efficiency than the ionic liquid catalyst (BMIPW 11 Zn). The TBAPW 11 Zn behaved as a homogeneous catalyst immobilized in the extraction solvent, while the ODAPW 11 Zn with the long carbon chain behaved as a heterogeneous catalyst capable to be recovered from the system. Both quaternary ammonium catalysts showed to be successfully reused/recycled for various consecutive desulfurization cycles. [ABSTRACT FROM AUTHOR]

The severe water pollution from effluent dyes threatens human health. This study created pH-magnetic-photocatalytic polymer microspheres to conveniently separate the photocatalyst nanoparticles from the treated water by applying an external magnetic field. While fabricating magnetic nanoparticles' (MNPs) microspheres, incorporating 0.5 wt.% iron oxide (Fe 3 O 4 ) showed the best magnetophoretic separation ability, as all the MNPs microspheres were attracted toward the external magnet. Subsequently, hybrid organic-inorganic polyoxometalates (HPOM), a self-synthesized photocatalyst, were linked with the functionalized magnetic nanoparticles (f-MNPs) to prepare augmented magnetic-photocatalytic microspheres. The photodegradation dye removal efficiency of the augmented magnetic-photocatalytic microspheres (f-MNPs-HPOM) was then compared with that of the commercial titanium dioxide (TiO 2 ) photocatalyst (f-MNPs-TiO 2 ). Results showed that f-MNPs-HPOM microspheres with 74 ± 0.7% photocatalytic removal efficiency better degraded methylene orange (MO) than f-MNPs-TiO 2 (70 ± 0.8%) at an unadjusted pH under UV-light irradiation for 90 min. The excellent performance was mainly attributed to the lower band-gap energy of HPOM (2.65 eV), which required lower energy to be photoactivated under UV light. The f-MNPs-HPOM microspheres demonstrated excellent reusability and stability in the photo-decolorization of MO, as the microspheres retained nearly the same removal percentage throughout the three continuous cycles. The degradation rate was also found to follow the pseudo-first-order kinetics. Furthermore, f-MNPs-HPOM microspheres were pH-responsive in the photodegradation of MO and methylene blue (MB) at pH 3 (acidic) and pH 9 (alkaline). Overall, it was demonstrated that using HPOM photocatalysts in the preparation of magnetic-photocatalytic microspheres resulted in better dye degradation than TiO 2 photocatalysts.

A new and practical promoter system for one-pot, efficient, chemoselective synthesis of 4-arylidene-2-phenyl-5(4 H)-oxazolones using [(CHN)WO]-[bmim]NO under solvent-free conditions is described. The present work opens up a new and ecofriendly synthetic route to Erlenmeyer-Plöchl adducts from primary benzyl alcohols in a one-pot operation. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]