Nankai University

About: Nankai University is a education organization based out in Tianjin, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 42964 authors who have published 51866 publications receiving 1127896 citations. The organization is also known as: Nánkāi Dàxué.

Metal–organic framework MIL-100(Fe) for the adsorption of malachite green from aqueous solution

Abstract: The adsorption of malachite green from aqueous solution on a highly porous metal–organic framework MIL-100(Fe) was studied in view of the adsorption isotherm, thermodynamics, kinetics, and regeneration of the sorbent. The adsorption isotherms of malachite green on MIL-100(Fe) followed the Freundlich model, and MIL-100(Fe) possessed heterogeneous surface caused by the presence of different functional groups on the surface. The adsorption of malachite green on MIL-100(Fe) is controlled by an entropy effect rather than an enthalpy change, and obeyed a pseudo-second-order kinetics. Analysis of the intraparticle diffusion plots revealed that more than one process affected the adsorption, and film (boundary layer) diffusion controlled the adsorption rate at the beginning. Evidence from zeta potential and X-ray photoelectron spectroscopic data showed that the adsorption of malachite green was also driven by electrostatic attraction and the interaction between the Lewis base –N(CH3)2 in malachite green and the water molecule coordinated metal sites of MIL-100(Fe). MIL-100(Fe) gave much higher adsorption capacity for malachite green than other conventional adsorbents such as activated carbon and natural zeolite. The high adsorption capacity, good solvent stability, and excellent reusability make MIL-100(Fe) attractive for the removal of MG from aqueous solution.

Li ion battery materials with core–shell nanostructures

Abstract: Nanomaterials have some disadvantages in application as Li ion battery materials, such as low density, poor electronic conductivity and high risk of surface side reactions. In recent years, materials with core–shell nanostructures, which was initially a common concept in semiconductors, have been introduced to the field of Li ion batteries in order to overcome the disadvantages of nanomaterials, and increase their general performances in Li ion batteries. Many efforts have been made to exploit core–shell Li ion battery materials, including cathode materials, such as lithium transition metal oxides with varied core and shell compositions, and lithium transition metal phosphates with carbon shells; and anode materials, such as metals, alloys, Si and transition metal oxides with carbon shells. More recently, graphene has also been proposed as a shell material. All these core–shell nanostructured materials presented enhanced electrochemical capacity and cyclic stability. In this review, we summarize the preparation, electrochemical performances, and structural stability of core–shell nanostructured materials for lithium ion batteries, and we also discuss the problems and prospects of this kind of materials.

Hematite (alpha-Fe2O3) with various morphologies: ionic liquid-assisted synthesis, formation mechanism, and properties.

Abstract: The α-Fe2O3 with various morphologies has been successfully synthesized via an ionic liquid-assisted hydrothermal synthetic method. The samples are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscope (FE-SEM), transmission electron microscopy, and high-resolution transmission electron microscopy. The results indicate that the as-prepared samples are α-Fe2O3 nanoparticles, mesoporous hollow microspheres, microcubes, and porous nanorods. The effects of the ionic liquid 1-n-butyl-3-methylimidazolium chloride ([bmim][Cl]) on the formation of the α-Fe2O3 with various morphologies have been investigated systematically. The proposed formation mechanisms have also been investigated on the basis of a series of FE-SEM studies of the products obtained at different durations. Because of the unique porous structure, the potential application in water treatment of the α-Fe2O3 porous nanorods was investigated. The UV−vis measurements suggest that the a...

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Abstract: Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.