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[Display omitted] In the context of industrialization and severe wastewater pollution, mercury ions pose a major threat due to their high toxicity. However, traditional adsorbents and common metal-organic framework (MOF) materials have limited effectiveness. This study focuses on combining magnetic materials with functionalized titanium-based MOF composite (SNN-MIL-125(Ti)@Fe 3 O 4) to improve mercury ion adsorption. Through comprehensive characterization and analysis, the adsorption performance and mechanism of the material were studied. The optimal adsorption of the material was achieved at pH 5, exhibiting a pseudo-second-order adsorption model and the Hill theoretical capacity of 668.98 mg/g. Hill and Tempkin models confirmed the presence of chemical and physical adsorption sites on the material surface. Thermodynamic experiments showed a spontaneous endothermic process. Despite the presence of interfering ions, the material exhibited high selectivity for mercury ions. After four cycles, adsorption performance decreased by only 8%, indicating excellent reusability. Nitrogen- and sulfur-containing functional groups played a key role in mercury ion adsorption. In conclusion, SNN-MIL-125(Ti)@Fe 3 O 4 , as a magnetic MOF adsorption material, showed potential for effective remediation of mercury-contaminated wastewater. This study contributes to the development of efficient adsorption materials and enhances the understanding of their mechanism. [ABSTRACT FROM AUTHOR]

To evaluate the synergetic adsorption capacity of layered double hydroxide (LDH) and photocatalytic reduction property of TiO 2 for aqueous Cr(VI), the Fe 3 O 4 -ZnAl-LDH and TiO 2 composites (FLT) were prepared via sol-gel method. The removal efficiency of FLT composites for Cr(VI) changed with the mass ratio of Fe 3 O 4 -LDH/TiO 2 , and the optimal ratio was 20% (FLT-2). The adsorption efficiencies of 100 mg FLT-2 were 74% and 64% for 20 and 50 mg/L Cr(VI) solution, and the total removal ratios of Cr(VI) were all over 97% after UV irradiation. The experimental data of adsorption kinetic, adsorption isothermal, and photocatalytic reduction were consistent with the pseudo-second-order, Langmuir, and first-order reaction equations, respectively. From the X–ray photoelectron spectra analysis, FLT composites adsorbed Cr(VI) directly via surface complexation, also reduced aqueous Cr(VI) to Cr(III). The photocurrent and electrochemical impedance spectroscopy of FLT composites indicated the photo-induced electron-hole pairs were separated effectively. The regeneration results show that the FLT composites had good stability and reusability after five consecutive cycles. Therefore, FLT composites are promising materials in the disposal of wastewater containing Cr(VI). [ABSTRACT FROM AUTHOR]

Abstract: We prepared tri-isocyanate reinforced graphene aerogel with a low bulk density (0.08g/cm3), high compressive failure strength (0.24MPa), and good adsorption ability towards crude oil (∼169mg/g), through self-assembly of graphene under hydrothermal condition, tri-isocyanate reinforcement and subsequent supercritical CO2 drying process. [Copyright &y& Elsevier]

Abstract: A low-temperature gas sorption study has been carried out on four three-dimensional microporous metal organic framework (MMOF) structures and two two-dimensional layered structures. The pore characteristics are analyzed based on the argon adsorption–desorption isotherms at 87K. The results from hydrogen sorption experiments conducted at 77 and 87K show that all MMOFs have a relatively high hydrogen uptake, with adsorbed hydrogen densities falling in the range of liquid hydrogen. Isosteric heats of hydrogen adsorption data calculated based on the Clausius–Clapeyron equation are consistent with these observations, indicating strong sorbent–sorbate interactions. [Copyright &y& Elsevier]

[Display omitted] • CAL and PPy-CAL were prepared using hydrothermal and in situ polymerization methods. • The theoretical adsorption capacity of CAL-PPy for Cr(VI) was nearly twice than that of CAL. • CAL-PPy removed 100 mg/L of aqueous Cr(VI) efficiently and quickly. • Mechanisms included electrostatic attraction, anion exchange, complexation, and reduction. To efficiently remove high concentrations of hexavalent chromium (Cr(VI)), calcium–aluminum-layered double hydroxide (CaAl-LDH, denoted as CAL), and polypyrrole-modified CAL (CAL-PPy) were prepared by hydrothermal and in situ polymerization methods, respectively. The chemical structure, morphology, and elemental results indicated that the chain-like polypyrrole was decorated with hexagonal CAL. The specific surface area of CAL-PPy increased from 8.746 m2/g to 24.24 m2/g. The adsorption performances of CAL and CAL-PPy for aqueous Cr(VI) were investigated using batch equilibrium experiments. The decontamination process of aqueous Cr(VI) (100 mg/L) reached the equilibrium state within 50 min, and the kinetic data met the pseudo-second-order kinetic equation. The Langmuir model described the isothermal data properly, and the obtained theoretical adsorption capacity of CAL for Cr(VI) at 318 K was 34.06 mg/g, while that of CAL-PPy was 66.14 mg/g. The removal mechanisms involved electrostatic attraction, surface complexation, anion exchange, and reduction to low-toxicity Cr(III). Therefore, CAL and CAL-PPy have underlying applications in treating real wastewater containing Cr(VI). [ABSTRACT FROM AUTHOR]

• MgAl-Cys-LDH had plentiful groups beneficial for the adsorption of metal ions. • Mechanisms included precipitation, surface complexation and isomorphic substitution. • MgAl-Cys-LDH presented higher removal efficiencies in real water environment. To understand the interaction mechanisms between heavy metals and functional groups modified nanomaterials, the l -cysteine (Cys) intercalated MgAl-layered double hydroxide (MgAl-Cys-LDH) was designed by a facile co-precipitation method and used to remove Cu(II), Pb(II) and Cd(II) in water solutions. The XRD, FTIR, SEM, TEM, EDS and XPS characterization analyses proved the carboxyl, thio and amido groups were successfully introduced into MgAl-LDH. The possible mechanisms were analyzed by the XPS and XRD spectra and involved the precipitation of metal hydroxides or sulfides, surface complexation with abundant surface groups, and the isomorphic substitution of Mg(II). The adsorption kinetics and isotherms data of Cu(II), Pb(II) and Cd(II) on MgAl-Cys-LDH were well described by the pseudo-second-order kinetic equation and the Langmuir model. The influence factors such as initial solution pH of heavy metals, dosage of MgAl-Cys-LDH, adsorption time and various types of water were investigated, and the results suggested that MgAl-Cys-LDH had potential applications in real wastewater treatment containing heavy metals. [ABSTRACT FROM AUTHOR]

• Catalytic synthesis of imines from a cascade reductive imination of nitroarenes with aldehydes. • High activity and selectivity of this cascade reduction to imines enabled by PtCo/CoBO x. • Competitive adsorption of reactants/products on PtCo/CoBO x for the high catalytic performance. Catalytic synthesis of imines from one-pot cascade hydrogen reductive imination of nitroarenes with aldehydes represents a facile, green and valuable process; however, such an economical process suffers from the poor chemoselectivity due to competitive hydrogenation of aldehydes and over-hydrogenation of imines into N -alkylated amines. Herein, bimetallic PtCo nanoparticles anchored on cobalt borate nanosheets (PtCo/CoBO x) can facilitate the unparalleled activity and selectivity towards imines through the same imination. The high chemoselectivity of imines is resulted from the competitive adsorption of reactants and products on PtCo/CoBO x , including (1) weakened adsorption of imines and its uncompetitive adsorption with aromatic amines (from nitroarenes) on bimetallic PtCo to minimize its over-hydrogenation; (2) competitive adsorption of nitroarenes on PtCo and preferential adsorption of aldehydes/nitroarenes on hydroxyl-enriched CoBO x through hydrogen bond formation to suppress hydrogenation of both aldehydes and imines; and (3) kinetically and competitively preferred reduction of nitroarenes over aldehydes to avoid hydrogenation of aldehydes. [ABSTRACT FROM AUTHOR]

Abstract: A multifunctional three-dimensional quaternary chalcogenide [Na5Zn3.5Sn3.5S13]·6H2O has been synthesized by solvothermal reactions. [Na5Zn3.5Sn3.5S13]·6H2O represents an interesting example of metal chalcogenides that combines semiconductivity, porosity, and light emission in a single structure. It crystallizes in the cubic space group Fm-3c, a=17.8630(3)Å, V=5699.85(17)Å3, Z=8. The compound decomposes at ∼450°C. A band gap of 2.9eV is estimated from the optical diffuse reflectance data. A strong photoluminescence peak is observed at 2.43eV in Mn doped samples. The electronic and optical properties of this compound can be systematically tuned by substitution of metal and chalcogen elements. [Copyright &y& Elsevier]