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(CoFe2O4)1-x/(Mg0.9Ni0.1O)x nanocomposites, with weight fraction x = 0, 0.1, 0.2, 0.4, 0.8 and 1, have been synthesized by co-precipitation method followed by high-speed ball milling technique. The structural and optical properties of the prepared samples have been studied. XRD analysis confirmed the formation of the two pure phases CoFe2O4 and Mg0.9Ni0.1O, without the formation of any impurities or minor phases in the nanocomposites. Transmission electron microscopy (TEM) followed by high-resolution TEM (HRTEM) and SAED were used to study the morphology, crystallinity and lattice spacing, respectively. TEM micrographs revealed the co-existence of spherical particles for both pure phases and their nanocomposites. The second-order kinetic model was employed to investigate the adsorption efficiency of the nanocomposites for removing malachite green (MG) dye from the solution. Among the prepared samples, superior adsorption performance was revealed by (CoFe2O4)0.2/(Mg0.9Ni0.1O)0.8 and Mg0.9Ni0.1O. (CoFe2O4)0.2/(Mg0.9Ni0.1O)0.8 nanocomposites were chosen as the best candidate among all samples as they possess magnetic properties which makes them easily removed from the solution after the adsorption process. Different adsorption isotherms (Langmuir, Freundlich, and Temkin isotherms) were used to determine the adsorption isotherm, and the results are consistent with the Langmuir theoretical model. The adsorption was further investigated by varying adsorbent concentration, pH of MG solution and reaction temperature. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles have emerged as a promising tool for wastewater treatment due to their unique properties. In this regard, Co0.33Mg0.33Ni0.33SmxFe2-xO4 (0.00 ≤ x ≤ 0.08) nanoparticles were prepared to examine their magnetic separation efficiency (MSE), photocatalytic, antibacterial, and antibiofilm performances. Pure nanoparticles, having the highest saturation magnetization (Ms = 31.87 emu/g), exhibit the highest MSE, where 95.6% of nanoparticles were separated after 20 min of applying a magnetic field of 150 mT. The catalytic performance of the prepared samples is examined by the photodegradation of rhodamine B (RhB) dye exposed to direct sunlight radiation. Improved photocatalytic activity is exhibited by Co0.33Mg0.33Ni0.33Sm0.04Fe1.96O4 nanoparticles, labeled as Sm0.04, where the rate of the degradation reaction is enhanced by 4.1 times compared to pure nanoparticles. Rising the pH and reaction temperature improves the rate of the photodegradation reaction of RhB. The incorporation of 15 wt% reduced graphene oxide (rGO) with Sm0.04 enhanced the rate of the reaction by 1.7 and 2.4 times compared with pure Sm0.04 sample and rGO, respectively. The antibacterial and antibiofilm activities against Escherichia coli, Leclercia adecarboxylata, Staphylococcus aureus, and Enterococcus faecium are assessed by the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) broth microdilution, the agar well diffusion, the time-kill assays, the biofilm formation, and destruction assays. The bacteria used in these assessments are isolated from wastewater. The nanoparticles exhibit a bacteriostatic activity, with a better effect against the Gram-positive isolates. Co0.33Mg0.33Ni0.33SmxFe2O4 (x = 0.00) nanoparticles have the best effect. The effect is exerted after 2–3 h of incubation. Gram-positive biofilms are more sensitive to nanoparticles. [ABSTRACT FROM AUTHOR]

A green, fast and selective approach for the synthesis of mono-substituted closo-decaborate derivatives [2-B10H9COR]2− has been established via a nucleophilic addition reaction between the carbonyl derivative of closo-decaborate [2-B10H9CO]− and the corresponding Grignard reagent RMgX, where R is the ethyl, iso-propyl, pentyl, allyl, vinyl and propynyl groups. This approach is accomplished under mild conditions with 70–80% yields. The significance of these derivative is their ability to constitute building blocks for polymeric integration via the allyl, vinyl and propynyl substituents. All products were characterized by 11B, 1H and 13C NMR, elemental analysis and mass spectrometry. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of Mg0.33Ni0.33Co0.33GdxFe2‐xO4 nanoparticles (NPs) with 0.00≤x≤0.08 by the co‐precipitation method. The structural and optical properties of NPs are investigated. As Gd content increases, the lattice parameter and the bandgap energy increase whereas the particle size decreases. The photocatalytic performance of NPs is evaluated in the degradation of methyl violet (MV) dye under sunlight irradiation. The best activity is exhibited by Mg0.33Ni0.33Co0.33GdxFe2‐xO4 where x=0.04. The rate of the photodegradation reaction is boosted by increasing the pH and temperature. 95.4 % of MV is degraded after 240 min upon the addition of 5 wt. % carbon dot. The NPs are tested against Gram‐positive (Staphylococcus aureus and Enterococcus faecium) and Gram‐negative bacteria (Escherichia coli and Leclercia adecarboxylata) isolated from wastewater. The antibacterial activity was tested by the minimum inhibitory concentration and minimum bactericidal concentration broth microdilution assay, agar well diffusion assay and time‐kill test. The results show that the NPs exhibit inhibitory activity against Gram‐positive bacteria. Furthermore, NPs show bacteriostatic activity after 3 hours of incubation. The antibiofilm activity of the NPs is tested by the inhibition of biofilm formation and the destruction of pre‐formed biofilm assays. The results show an inhibitory activity of the NPs against Gram‐positive biofilms. [ABSTRACT FROM AUTHOR]

This investigation reports the synthesis and characterization of (1-x)Ni0.5Zn0.5Fe2O4/(x)Zn0.95Co0.05O nanocomposites, with 0.0 ≤ × ≤ 0.5. Fourier transform infrared (FTIR) and Raman spectroscopies confirmed the purity of the samples and the presence of bands corresponding to octahedral and tetrahedral iron occupancies for Ni0.5Zn0.5Fe2O4 nanoparticles. A shift in peak positions of these bands was detected upon the addition of Zn0.95Co0.05O nanoparticles. The magnetic properties of the nanocomposites were examined using Mössbauer spectrometry at both room temperature and 77 K. Room temperature analysis showed the existence of both ferromagnetic and superparamagnetic behaviors, while at 77 K, all nanocomposites showed ferromagnetic behavior. The adsorption performance of the nanocomposite on the removal of malachite green (MG) dye solution was investigated by varying the contact time, adsorbent concentration, and reaction temperature. The adsorption reaction followed the second-order kinetics and the sample with x = 0.3 showed the highest adsorption rate. The adsorption rate showed an increase with the increase in the reaction temperature. The adsorption isotherm was determined by applying different adsorption isotherms (Langmuir, Freundlich, and Temkin isotherms), and the results are well-fitted with the Langmuir theoretical model. [ABSTRACT FROM AUTHOR]

The increase in environmental pollution, especially water pollution, has intensified the requirement for new strategies for the treatment of water sources. Furthermore, the improved properties of nano-ferrites permit their usage in wastewater treatment. In this regard, novel Mg0.33Ni0.33Co0.33LaxFe2−xO4 nanoparticles (NPs), where 0.00≤x≤0.08, were synthesized to test their photocatalytic, antibacterial and antibiofilm activities. The structural and optical properties of the prepared NPs were investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), UV-Vis spectroscopy and photoluminescence (PL) analysis. As La content increases, the bandgap energy increases, whereas the particle size decreases. The photocatalytic activity of the prepared NPs is evaluated by the degradation of methylene blue (MB) dye under sunlight irradiation. Superior activity is exhibited by Mg0.33Ni0.33Co0.33La0.01Fe1.99O4 NPs. The influence of catalyst dosage, pH, temperature and addition of graphene (Gr) on the photodegradation reaction was studied. Increasing the pH and temperature improved the rate of the photodegradation reaction. The antibacterial and antibiofilm activities of the NPs were assessed against Escherichia coli, Leclercia adecarboxylata, Staphylococcus aureus and Enterococcus faecium. Mg0.33Ni0.33Co0.33Fe2O4 NPs inhibited bacterial growth. They had bacteriostatic activity on all isolates, with a greater effect on Gram-positive bacteria. All tested nano-ferrites had significant antibiofilm activities against some biofilms. [ABSTRACT FROM AUTHOR]

Closo‐decahydrodecaborate anion, [B10H10]2−, is one of the most notable clusters in the family of hydroborates, partly attributed to its unique electronic structure and its thermal and chemical stability. The major challenge in the development of [B10H10]2− chemistry resides in its functionalization via the activation of exo‐polyhedral B−H bonds to B−L bonds to generate attractive molecular construction modules or 'archetypes' of useful applications. To date, the closo‐[B10H10]2− cage has been functionalized with a wide range of functional groups ‐L such as halogens, amines, thiols, alkoxy, hydroxyl and multifunctional moieties to yield mono‐ or poly‐substituted borate derivatives. In this review, we present the recent trends in the chemistry of closo‐decaborate with focus on the substitution reactions of hydrogen atoms by various entities. [ABSTRACT FROM AUTHOR]

The magnetic properties of the pentacoordinate [MII(Me4cyclam)N3]+ (Me4cyclam=tetramethylcyclam; N3=azido; M=Ni, Co) complexes were investigated. Magnetization and EPR studies indicate that they have an easy plane of magnetization with axial anisotropy parameters D close to 22 and greater than 30 cm−1 for the Ni and Co complexes, respectively. Ab initio calculations reproduced the experimental values of the zero-field splitting parameters and allowed the orientation of the anisotropy tensor axes with respect to the molecular frame to be determined. For M=Ni, the principal anisotropy axis lies along the Ni−Nazido direction perpendicular to the Ni(Me4cyclam) mean plane, whereas for M=Co it lies in the Co(Me4cyclam) mean plane and thus perpendicular to the Co−Nazido direction. These orientations match one of the possible solutions experimentally provided by single-crystal cantilever torque magnetometry. To rationalize the geometry and its impact on the orientation of the anisotropy tensor axis, calculations were carried out on model complexes [NiII(NCH)5]2+ and [CoII(NCH)5]2+ by varying the geometry between square pyramidal and trigonal bipyramidal. The geometry of the complexes was found to be the result of a compromise between the electronic configuration of the metal ion and the structure-orienting effect of the Me4cyclam macrocycle. Moreover, the orientation of the anisotropy axes is mainly dependent on the geometry of the complexes. [ABSTRACT FROM AUTHOR]