Preparation and Characterization of Cu_3V_2O_7(OH)_2·2H_2O Hollow Spheres from Na_2V_6O_16·3H_2O Nanobelts

Monoclinic Cu3V2O7(OH)2·2H2O(copper polyvanadate) hollow spheres were prepared with Na2V6O16· 3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, Raman spectroscopy, thermogra-vimetric analysis(TGA) and X-ray photoelecton spectroscopy(XPS). The morphology and size were observed by scanning electron microscopy(SEM). We found that the Kagomé staircase-structural copper...     

PREPARATION AND CHARACTERIZATION OF AMIDATED PECTIN BASED POLYMER ELECTROLYTE MEMBRANES

The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA) and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(Y_M and K_N) are ca...     

Two highly porous single-crystalline zirconium-based metal-organic frameworks

Herein we report two highly porous Zr-based metal-organic frameworks(MOFs, 1 and 2) constructed by the truncated octahedral secondary building unit(SBU) of Zr_6O_4(OH)_4(CO_2)_(12) and the organic linear ligand of 4,4.-stilbenedicarboxylic acid(H_2sbdc) or4,4′-azobenezenedicarboxylic acid(H_2abdc). Both Zr-based MOFs are obtained as single crystals of suitable size for single-crystal X-ray diffraction analysis. Furthermore, these two Zr-based MOFs have been fully characterized by powder X-ray diffraction(PXRD) studies, thermogravimetric analysis(TGA), infrared spectroscopy(IR) and gas adsorption analysis. In particular, their CO_2 gas adsorption behaviors have been investigated and discussed.     

Preparation of chloro-functionalized reduced graphene oxide by silver-catalyzed radical reaction

It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide(rGOCl).The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide(GOCOOH) with N-chlorosuccinimide(NCS) at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide(GO) in three steps.     

Synthesis and Characterization of Samarium （Ⅲ） Containing Poly-（N-vinylacetamide） Complex

Poly (N-vinylacetamide) (PNVA) was synthesized by the free radical polymerization and its samarium (Ⅲ) binary complex was prepared and characterized by means of IR, UV-vis, X-ray photoelectron spectroscopy (XPS) and fluorescence spectra. The fluorescent intensity of samarium (Ⅲ) characteristic emission was increased significantly due to efficient energy transfer from polymeric ligand to Sm (Ⅲ) ion in the complex.     

Effect of Copper Substitution and Preparation Methods on the LaMnO3 Structure and Catalysis of Methane Combustion and CO Oxidation

 LaMn1-xCuxO3刡冊 perovskite oxides (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were prepared by two different methods, the Pechini and sol-gel methods. The catalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray fluorescence spectroscopy, N2 adsorption, and temperature-programmed reduction. Their catalytic activity in the oxidation of methane and CO was evaluated. EDS and SEM results showed that the Pechini samples had more homogeneity and smaller particles (higher specific surface area). The catalytic activity for methane combustion was highest for x = 0.2. In CO oxidation, the oxides with x = 0.2 and x = 0.4 were the most active. The Pechini samples had higher activity and stability than the sol-gel samples.     

THE STRUCTURE AND PROPERTIES OF CHITOSAN/POLYETHYLENE GLYCOL/SILICA TERNARY HYBRID ORGANIC-INORGANIC FILMS

The ternary hybrid films consisting of chitosan(CS),polyethylene glycol(PEG)and nano-sized silica which was surface-modified by amino groups(RNSA)were prepared.The structures of the blend membranes were characterized by attenuation total reflection-infrared spectroscopy(ATR-IR),X-ray diffraction(XRD),optical microscopy(OM)and differential scanning calorimetry(DSC).The results showed that the addition of silica affected not only the distribution and crystallinity of PEG on the sample surface,but also the ...     

SnO2纳米粒子的制备与表征

The SnO2 nano-particles with rutile structure were prepared by a Water/Oil (W/O) microemulsion system, composed of Triton X-100 1-hexanol/Cyclohexane/Water. The particles were also compared with that synthesized by citric acid method. The powders were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared spectroscopy (IR). The result showed that the SnO2 particles prepared by microemulsion had fine shape and narrow range of particle size distribution. The crystallite size calcined at 600℃ was 11.49 nm,while the crystallite size prepared by citric acid method was about 17.4 nm.     

Synthesis of KNiF3 with Lower Oxygen Content by Refluxing Method

The complex fluoride,KNiF3,with perovskite structure was synthesized by refluxing KF and Ni(NO3)2·6H2O in ethanediol.The samples were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),and ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS).The results indicate that the mean diameter of KNiF3 particles is about 30―60 nm and the oxygen content in the samples is≤5%.The prepared KNiF3 shows obvious absorption peaks at 400―830 nm.     

Analysis and Protection of One Thousand Hand Buddha in Dazu Stone Sculptures

The components of the rock, the pigments, the gold foils and the adhesive of One Thousand Hand Buddha in Dazu stone sculptures, Chongqing, China, have been analyzed by X-ray diffraction (XRD), X-ray fluorescence (XRF), infrared spectroscopy (IR), energy dispersive X-ray analysis (EDX) and fiber optics reflectance spectroscopy (FORS). Furthermore, the weathering and degeneration of One Thousand Hand Buddha have been discussed and the protective methods have been provided. In this work some useful information to study on conservation of stone relics is given.     

金属有机骨架化合物催化合成不对称有机碳酸酯

金属有机骨架化合物(MOFs)是通过过渡金属和有机配体的自组装形成的一类新型材料, 具有高表面积、多孔性、孔尺寸可调等优点, 在催化、分离和气体储存等方面得到广泛应用. 用三种不同方法制备了金属有机骨架化合物, 并用扫描电镜(SEM)、X射线衍射(XRD)和红外(IR)光谱等方法进行了表征. 结果表明, 用不同方法制备的MOFs表现出不同的结构和形貌, 用直接混合法制备的MOFs是有效的催化碳酸二乙酯与醇酯交换制备有机碳酸酯的多相催化剂. 系统地考察了反应时间、反应温度、催化剂用量和底物摩尔比对反应的影响, 结果表明, 碳酸二乙酯与芳香醇、脂环醇、脂肪醇和杂环醇均能以100%选择性高产率地合成有机碳酸酯, 固体催化剂经简单离心分离可重复使用至少2次.     

Studies on the adsorption behaviors of Pb(II) onto an acyl-thiourea resin

In this paper, an acyl-thiourea resin (PIDTR) was synthesized and its adsorption performances to Pb(II) were investigated by adsorption tests, scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses. A pH of 6.0 was found to be the optimum pH to obtain the maximum adsorption capacity in 12 hours of equilibration time. The Langmuir model was well fitted to the adsorption data with adsorption capacity of 0.756?mmol?·?g^?1. The adsorption kinetics showed that the adsorption process experienced liquid film diffusion and chemical reaction. The thermodynamic studies indicated that the adsorption for Pb(II) was spontaneous and endothermic. The results of SEM suggested that Pb(II) adsorbed on the surface of PIDTR. The FTIR and XPS analyses further confirmed Pb(II) might chemisorb onto PIDTR surfaces and N–Pb, O–Pb, and S–Pb were formed with the breakage of C?O, C?S, and N-H bonds in the PIDTR molecule.     

Achieving Morphological Control over Lamellar Manganese Metal-Organic Framework through Modulated Bi-Phase Growth

A modulated bi-phase synthesis towards large-scale manganese 1,4-benzenedicarboxylate (MnBDC) MOFs with a precise control over their morphology (bulk vs. layered) is presented. Metal precursors and organic ligands are separated to reduce the kinetic reaction rates for better control over the crystallization process. Based on scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy studies, the continuous ligand supply along with the presence of pyridine capping agent are highly effective in promoting the layer-by-layer growth and achieving large crystal sizes. Once layered MnBDC is stabilized, topotactic intercalation chemistry was used to demonstrate the feasibility of bromine intercalation on these layered materials. Bromine intercalation is possible between the MOFs layers for the first time. Bromine intercalation causes colossal reduction in layered MnBDC band gap while it has no observable effect on bulk MOFs.     

Removal of Pb(II) ions from aqueous solutions on few-layered graphene oxide nanosheets

Few-layered graphene oxide (FGO) was synthesized from graphite by using the modified Hummers method, and was characterized by scanning electron microscopy, atomic force microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. The prepared FGO was used to adsorb Pb(II) ions from aqueous solutions. The abundant oxygen-containing groups on the surfaces of FGO played an important role in Pb(II) ion adsorption on FGO. The adsorption of Pb(II) ions on FGO was dependent on pH values and independent of ionic strength. The adsorption of Pb(II) ions on FGO was mainly dominated by strong surface complexation. From the adsorption isotherms, the maximum adsorption capacities (C(smax)) of Pb(II) ions on FGO calculated from the Langmuir model were about 842, 1150, and 1850 mg g(-1) at 293, 313, and 333 K, respectively, higher than any currently reported. The FGO had the highest adsorption capacities of today's nanomaterials. The thermodynamic parameters calculated from the temperature dependent adsorption isotherms indicated that the adsorption of Pb(II) ions on FGO was a spontaneous and endothermic process.     

Assessment of adsorption properties of inorganic–organic hybrid cyclomatrix type polyphosphazene microspheres for the removal of Pb(II) ions from aqueous solutions

Abstract

Inorganic–organic hybrid cyclomatrix type polyphosphazene microspheres (poly[cyclotriphosphazene-co-(4,4′-diaminodiphenylmethane)]) (HDMS) and poly[cyclotetraphosphazene-co-4,4′-diaminodiphenylmethane)] (ODMS) were prepared to investigate their possible use as alternative adsorbents for the comparative study on Pb(II) ions removal from aqueous solutions. The structures of the microspheres were elucidated by Fourier Transform Infrared (FTIR) spectroscopy and Dynamic Light Scattering (DLS) measurements, and the surface morphologies were also observed by Scanning Electron Microscopy (SEM). The adsorption of Pb(II) ions onto HDMS and ODMS from aqueous solutions was examined by means of pH, temperature, contact time and concentration. Furthermore, adsorption kinetics and isotherm models were applied and the experimental data fitted well with Langmuir isotherm and pseudo-second-order kinetic models. The maximum adsorption capacities of HDMS and ODMS for Pb(II) ions were obtained as 157.8 and 308.0?mg g^?1 at 20?°C and pH 5.5, respectively.     

Microplasma electrochemistry (MIPEC) strategy for accelerating the synthesis of metal organic frameworks at room temperature

Metal organic frameworks(MOFs) are a kind of promising materials in many applications,while the fast and controllable synthesis of MOFs is still challenging.Here,taking HKUST-1 as illustration,a microplasma electrochemistry(MIPEC) strategy was developed to accelerate the synthesis process of MOFs with micro-plasma acting as cathode.Treating the HKUST-1 precursor solution with micro-plasma cathode could not only transfer the electrons into the solution leading to the deprotonation effect,but also generate radical species to trigger and accelerate the nucleation and growth of MOFs at the plasmaliquid interface.Thus,uniform and nanosize MOFs could be prepared within minutes.The obtained MOFs show similar excellent uranium adsorption properties compared with those obtained by other method,with a highly adsorption capability of uranium with 550 mg/g in minutes.The novel MIPEC strategy developed in this work provides an alternative for controllable synthesis of MOFs,and especially has potential application in accelerating traditional organic synthesis.     

SiO2/graphene composite for highly selective adsorption of Pb(II) ion

SiO(2)/graphene composite was prepared through a simple two-step reaction, including the preparation of SiO(2)/graphene oxide and the reduction of graphene oxide (GO). The composite was characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscope, and X-ray photoelectron spectroscopy, and what is more, the adsorption behavior of as-synthesized SiO(2)/graphene composite was investigated. It was interestingly found that the composite shows high efficiency and high selectivity toward Pb(II) ion. The maximum adsorption capacity of SiO(2)/graphene composite for Pb(II) ion was found to be 113.6 mg g(-1), which was much higher than that of bare SiO(2) nanoparticles. The results indicated that SiO(2)/graphene composite with high adsorption efficiency and fast adsorption equilibrium can be used as a practical adsorbent for Pb(II) ion.     

Crosslinked chitosan nanofiber mats fabricated by one-step electrospinning and ion-imprinting methods for metal ions adsorption

The Pb(Ⅱ)ion-imprinting electrospun crosslinked chitosan nanofiber mats were fabricated by one-step electrospinning and ion-imprinting methods and their application as adsorbents for metal ions was also investigated.The resulting chitosan nanofiber mats were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and thermal gravimetric analysis(TGA).The Pb(Ⅱ)ion-imprinting electrospun crosslinked chitosan nanofiber mats were used as adsorbents for the removal of Pb(Ⅱ)ions from aqueous or acid solutions.The effects of p H values,contact time,content of crosslinker(glutaraldehyde)on Pb(Ⅱ)ions adsorption were studied.The results indicated that the Pb(Ⅱ)ion-imprinting electrospun crosslinked chitosan nanofiber mats had the highest adsorption capacity of 110.0 mg/g at p H 7.The kinetic study demonstrated that the adsorption of Pb(Ⅱ)ions followed the pseudo-second-order model.The equilibrium isotherm data showed that the Langmuir model was the most suitable for predicting the adsorption isotherm of the studied system.The Pb(Ⅱ)ion-imprinting electrospun crosslinked chitosan nanofiber mats had good adsorption selectivity,which illustrates the equilibrium adsorption capacity in the order of Pb(Ⅱ)Cu(Ⅱ)Zn(Ⅱ)Cd(Ⅱ)Ni(Ⅱ).The Pb(Ⅱ)ion-imprinting electrospun crosslinked chitosan nanofiber mats were stable and had good reuse ability.     

Sol–gel derived ion-imprinted silica-supported organic–inorganic hybrid sorbent for selective removal of lead(II) from aqueous solution

The current paper presents a novel Pb(II) ion-imprinted silica-supported organic–inorganic hybrid sorbent functionalized with Schiff base by coupling a surface imprinting technique with a sol–gel process for the selective removal of Pb(II) ions from aqueous solution. Fourier transmission infrared spectroscopy, scanning electron microscopy, N₂ adsorption–desorption isotherms and thermogravimetric analysis were used to characterize the Pb(II)-imprinted hybrid sorbent. The adsorption equilibrium was finished with 30 min. The experiment value of maximum adsorption capacity was found to be 54.9 mg g^?1. There were not significantly influence on the adsorption capacity of Pb(II) in the range of pH 3.5–6.5. The equilibrium data were fitted very well to the Langmuir isotherm model and pseudo-first-order kinetics model. Under competitive adsorption conditions, the Pb(II)-imprinted hybrid sorbent was 3.09, 4.73, 3.34 and 4.96 times more selective than the corresponding non-imprinted sorbent for the systems of Pb(II)/Cu(II), Pb(II)/Cd(II), Pb(II)/Ni(II) and Pb(II)/Zn(II), respectively. The thermodynamic results demonstrated that the adsorption of Pb(II) onto the Pb(II)-imprinted hybrid sorbent took place by a spontaneous and endothermic process with further increase in the degree of freedom at the solid–solution interface.