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1.
R. Gadiou A. Didion D.A. Ivanov R. Kötz 《Journal of Physics and Chemistry of Solids》2008,69(7):1808-1814
The negative templating synthesis process has been applied to prepare nanostructured carbon materials with a high nitrogen content. SBA-15 silica template was impregnated with the following carbon precursors: sucrose, glucose and amino-glucose. The structure of the materials was investigated by SAXS, WAXS and TEM. Nitrogen functions were analyzed by XPS and the textural parameters of the carbons were studied by nitrogen and CO2 adsorption. X-ray and TEM studies confirmed that a pore nanostructure is inherited from the silica templates. XPS analysis showed that the nitrogen content of the materials can be controlled between 2 and 5 wt% and that N atoms are strongly bonded in the carbon structure in heterocycles or nitrile functions. An important result is that these nanostructured carbon materials exhibits interesting textural properties with BET surface areas ranging between 1000 and . Moreover, the study of the influence of nitrogen on the textural and structural parameters of the resulting carbon materials shows that nitrogen plays an active role during the synthesis process. This observation is also supported by the speciation of nitrogen in the nanostructured carbon materials. 相似文献
2.
New dicarboxylate-functionalized pillared materials with a general formula of λ-ZrPO4(OH)1-x(OOC(CH2)nCOO)x/2(dmso) (n=6, 8 and 10) have been prepared by post-synthesis modification of the inorganic layers of λ-zirconium phosphate (λ-ZrP), where the superficial Chloride monovalent anionic ligands of λ-layer are partially exchanged with the divalent anionic ligands of a series of long-chain aliphatic dicarboxylic acids, namely octanedioic acid, decanedioic acid and dodecanedioic acid. The synthesized materials are characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental and thermogravimetric analyses. The X-ray diffraction patterns show that the obtained solid phases are pure. Furthermore, the interlayer distance of λ-ZrP systematically increases from 1.02 to 1.59 nm as a result of the incorporation of the mentioned acids inside the interlayer gallery. 相似文献
3.
Mariana Noelia Barroso Julio Andrade Gamboa Maria Cristina Abello 《Journal of Physics and Chemistry of Solids》2006,67(7):1583-1589
CuZnAl catalysts with different Cu loading (1-23 wt%) and a Zn:Al atomic ratio nearly constant (Zn:Al≅0.6), were prepared by the citrate sol-gel method and characterized by different techniques such as TG, BET, TPR, XRD and FTIR. The final structure obtained was strongly influenced by the calcination temperature and metal precursor composition. XRD and quantitative Rietveld revealed Zn and Al species were mainly incorporated into the normal spinel matrix and copper predominantly forms CuO. The formation of a ZnAl2O4 spinel was favored by increasing Cu amounts and/or by increasing calcination temperature (from 500° to 700 °C). The spinel phase of the catalysts calcined at 700 °C, had a good thermal stability and it was preserved after TPR measurements. Under hydrogen atmosphere Cu2+ was fully reduced to Cu0. Although the composition and the calcination temperature have a strong influence on the phase nature in CuZnAl catalysts, the reducibility of Cu species changes in a non significant way. 相似文献
4.
Tsung-Yen Tsai Chun-Yi Lee Wei-Chiang Chang Po-Cheng Chen 《Journal of Physics and Chemistry of Solids》2010,71(4):595-599
This work describes the morphology and electro-optical properties of polymer-dispersed liquid crystals (PDLCs). These composites consist of the nematic liquid crystal E7, filled with different types of inorganic nanoparticles in Norland optical adhesive (NOA65) polymer matrices. Natural clays CL120 (trade name: CN-C34 with higher cation exchange capacity CEC) and CL42 (trade name: PK802 with lower CEC) are used as various inorganic nanofillers. Wide angle X-ray diffraction was exploited to examine the dispersion of the inorganic nanoparticles in PDLCs. The morphology of liquid crystal droplets in PDLCs is investigated by the field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) as well. Transmittance vs. applied voltage is measured to study the electro-optical properties and the response times of the PDLCs. It is suggested that doping with inorganic nanoparticles in PDLCs effectively reduces the driving voltage and improves the electro-optical characteristics. 相似文献
5.
Macroporous nanocrystalline (Sr,Pb)TiO3 solid solutions were prepared by a facile self-propagating combustion method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). (Sr,Pb)TiO3 solid solutions showed enhanced photocatalytic activity for the degradation of methyl orange (MO) than pure SrTiO3 and an optimum performance was observed for Sr29/32Pb3/32TiO3. The possible mechanism for the enhanced photocatalytic activity on (Sr,Pb)TiO3 solid solutions was proposed. 相似文献
6.
Preparation and characterization of polymer coated superparamagnetic magnetite nanoparticle agglomerates 总被引:1,自引:0,他引:1
Bilsen Tural Necati Özkan Murvet Volkan 《Journal of Physics and Chemistry of Solids》2009,70(5):860-9097
In order to produce magnetic microparticles (agglomerates), magnetite (Fe3O4) particles were synthesized using coprecipitation of FeSO4·7H2O and FeCl3·6H2O with the presence of poly(methacrylic acid) (PMAA) in aqueous solution.. Transmission electron microscopy (TEM), X-ray diffraction, and vibrating sample magnetometry (VSM) methods were used to characterize the PMAA coated superparamagnetic agglomerates. The influences of various processing parameters such as the process temperature, PMAA content, and the addition of surfactant on the agglomerate size and size distribution of produced magnetic microparticles were investigated. The particle size and size distribution characteristics, (the volume weighted mean size (D[4,3], surface weighted mean size D[3,2], the geometric standard deviation, and span value) of the magnetic agglomerates were determined using the laser diffraction technique. The PMAA coated magnetic agglomerates with surface weighted mean sizes ranging from 1.5 to 3 μm were produced successfully. 相似文献
7.
Xiang-Dong Zhang Zhong-Shuai Wu Da Li 《Journal of Physics and Chemistry of Solids》2007,68(8):1583-1590
Hydrothermal method had been used to successfully synthesize the nanocrystalline spinel zinc manganese oxide (ZnMn2O4) directly from Zn(CH3COO)2·2H2O, NaOH, Mn(NO3)2 and H2O2 at 170 °C for the reaction time of 48 h. The effects of the synthesis conditions, such as the Zn/Mn molar ratio, the reaction temperature, the reaction time, the zinc source and the concentrations of NaOH and H2O2, on the formation of the Zn-Mn spinel were investigated. The products were characterized by means of X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results indicated that the compositions of the Zn-Mn spinel with the tetragonal structure were Zn1.14Mn1.86O4. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) images showed that the products at 170 °C were with square-shaped nanocrystalline spinel with the particle size of about 20-50 nm. The thermal behaviors of the products were investigated by thermogravimetric analysis (TG). 相似文献
8.
Yingchao Zhang 《Journal of Physics and Chemistry of Solids》2010,71(4):604-7300
NiFe2O4/NiO nanocomposite thin films have been successfully prepared through a facile route using nickel iron layered double hydroxide (NiFe-LDH) as a single-source precursor. This synthetic approach mainly involves the formation of NiFe-LDH film by casting the slurry of NiFe-LDH precursor on the α-Al2O3 substrate, followed by high-temperature calcination. The composition, microstructure and properties of the films were characterized in detail by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and vibrating sample magnetometer (VSM). The results indicate that NiFe2O4/NiO composite film was composed of granules with diameter less than 100 nm, and the thickness of the film was in the range 1-2 μm. The magnetization of the film can be tuned by alternating the Ni/Fe molar ratio of LDH precursor. In addition, the method developed should be easily extended to fabricate other MFe2O4/MO composite film systems with specific applications just by an appropriate combination of divalent/trivalent composition in the precursor of LDHs. 相似文献
9.
Preparation, conversion, and comparison of the photocatalytic property of Cd(OH)2, CdO, CdS and CdSe
In this paper, we report the hydrothermal preparation of Cd(OH)2 nanowires and further conversion to CdO nanobelts, CdS nanowires and CdSe nanoparticles through thermal treatment, solvothermal and mixed-solvothermal routes, respectively. The as-obtained products were characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FEMSEM). Research showed that four cadmium compounds were good photocatalysts for the degradation of organic dyes such as Safranine T and Pyronine B, under irradiation of 365 nm UV light. The order of catalytic activity of different materials was found to be Cd(OH)2<CdO<CdS<CdSe. 相似文献
10.
The potential of using encapsulation by MEA, DEA and TEA to control the morphology of ZnO powders was investigated. The crystallite and particle size decreased as a function of aminoalcohol concentration. We found that aminoalcohols can inhibit the crystal growth of ZnO along the c-axis. A steric effect by TEA more strongly influenced the formation of different ZnO shapes than did MEA and DEA. The value of the band gap was dependent on the crystallite size, particle size and particle shape. 相似文献
11.
Ji Eun Ko 《Journal of Physics and Chemistry of Solids》2010,71(4):658-662
SnO2-pillared titanate nanohybrid has been prepared by reacting the exfoliated layered titanate sheets with the nanosized SnO2 sol particles. The stable two-dimensional colloidal nanosheets could be obtained by intercalating tetrabutylammonium cation into the layered protonic titanate, HxTi2−x/4□x/4O4·H2O (x=0.67) with a lepidocrocite-like structure, and by successive exfoliation process in an aqueous solution. Monodispersed SnO2 nano sol particles were prepared by hydrolysis of SnCl4·5H2O in the presence of sodium hydroxide, and then the exfoliated titanate suspension was mixed with SnO2 nano sol solution until the flocculated products formed. The final product was heated at various temperatures in order to complete the grafting reaction of intercalated SnO2 nano sol on the interlayer surface of layered titanate. Inductive coupled plasma, X-ray diffraction, thermal analysis and N2-adsorption-desorption isotherms were carried out to study the hybridizing process and the structure of SnO2-pillared titanate nanohybrid. 相似文献
12.
Liling Guo Hanxing Liu Yadong Dai Shixi Ouyang 《Journal of Physics and Chemistry of Solids》2007,68(9):1663-1673
The series of the hybrids (CnH2n+1NH3)2FeCl4, where n=2, 4, 6, 8, 10 and 12, were synthesized in HCl solutions. The optimum conditions of synthesis were investigated including the sequence of adding reactants, the stoichiometric ratio of the reactants, the reaction time and the drying procedures. The results demonstrate that the order of adding reactants, the drying temperature and drying time have little effect on the structures of the products. But for the hybrids of n?10, longer reaction time is needed to form the layered structures. The X-ray diffraction (XRD) patterns and the images of scanning electron microscopy of the products demonstrate that the hybrids crystallize well with typical layered structures. Chemical analysis of C, H and N confirms that the hybrids consist of the elements in the ratio of the molecular formulas. The d values, the interlayer distance between the two adjacent inorganic sheets of each hybrid, are obtained from the XRD patterns and they suggest that the organic chains interdigitate between the inorganic sheets. The longer the organic chains are, the more interdigitations there are. This can be explained by the different interaction strengths between the organic species when the chain lengths change. These different interactions can also explain the phenomena observed in the synthesis and the decomposing temperatures of the hybrids. 相似文献
13.
Monica Sorescu L. Diamandescu D. Tarabasanu-Mihaila B.H. Howard 《Journal of Physics and Chemistry of Solids》2004,65(5):1021-1029
Structural and morphological characteristics of (1−x)α-Fe2O3-xSnO2 (x=0.0-1.0) nanoparticles obtained under hydrothermal conditions have been investigated by X-ray diffraction (XRD), transmission Mössbauer spectroscopy, scanning and transmission electron microscopy as well as energy dispersive X-ray analysis. On the basis of the Rietveld structure refinements of the XRD spectra at low tin concentrations, it was found that Sn4+ ions partially substitute for Fe3+ at the octahedral sites and also occupy the interstitial octahedral sites which are vacant in α-Fe2O3 corundum structure. A phase separation of α-Fe2O3 and SnO2 was observed for x≥0.4: the α-Fe2O3 structure containing tin decreases simultaneously with the increase of the SnO2 phase containing substitutional iron ions. The mean particle dimension decreases from 70 to 6 nm, as the molar fraction x increases up to x=1.0. The estimated solubility limits in the nanoparticle system (1−x)α-Fe2O3-xSnO2 synthesized under hydrothermal conditions are: x≤0.2 for Sn4+ in α-Fe2O3 and x≥0.7 for Fe3+ in SnO2. 相似文献
14.
Swarup Kumar Maji Anup Mondal Bibhutosh Adhikary Basudeb Karmakar 《Journal of Physics and Chemistry of Solids》2011,72(6):784-788
We report the formation of mesoporous zinc sulphide, composed by the fine network of nanoparticles, which was formed via a single precursor Zn(SOCCH3)2Lut2 complex. The complex was chemically synthesized using zinc carbonate basic, 3,5-lutidine and thioacetic acid, in air. The metal precursor complex was characterized using different conventional techniques. Thermogravimetric analysis (TGA) result indicates that the decomposition of the complex starts at 100 °C and continues up to 450 °C, finally yielding ZnS. ZnS nanocrystals were characterized by powder X-ray diffraction (XRD) technique, field emission scanning electron microscopy (FESEM), N2-sorption isotherm, UV-vis spectroscopy and photoluminescence (PL) spectroscopy. The grain diameter of nanocrystals was found to be 4-5 nm. The material followed Type-IV N2-sorption isotherm, which is the characteristic of mesoporous materials. The band gap energy, as obtained from optical measurements was around 3.8 eV. 相似文献
15.
The purpose of this work is to study the incorporation of nitrogen into barium titanate at oxygen sites by ammonolysis. The nitrogen content of the resulting barium titanate powders strongly depends on the flow rate of ammonia and the ratio Ba/Ti. The amount of resulting oxygen vacancies is lowered by co-doping with fluoride and tantalum.By avoiding an excess of BaO and exchanging 10 mol% Ti by Ta it is possible to produce powders with nitrogen content of more than 1 wt%. Partial substitution of barium oxide by barium fluoride also increases the nitrogen content. The nitrogen containing powders are colored and show an additional absorption at 500 nm measured in the UV/vis reflectance spectrum. The concentrations of nitrogen and fluorine in the samples were determined using ion-sensitive electrodes. X-ray powder diffraction shows the composition of the powders. The thermal stability was investigated by thermogravimetric analysis, and in order to calculate the specific surface area the three-point BET method was used. 相似文献
16.
Watcharee Katinonkul 《Journal of Physics and Chemistry of Solids》2007,68(3):394-399
A new graphite intercalation compound containing the bis(oxalato)borate anion, B[OC(O)C(O)O]2−, is prepared for the first time by chemical oxidation of graphite with fluorine gas in the presence of a solution containing the intercalate anion in anhydrous hydrofluoric acid. The products of stage 1-3 compounds are characterized by powder X-ray diffraction, thermogravimetric analysis, and elemental analyses. X-ray diffraction data indicate a standing-up orientation for the borate anion, with long axis perpendicular to the graphene sheets. Elemental analyses provide x and δ for the nominal composition of CxB[OC(O)C(O)O]2·δF, where the chelate borate and fluoride are co-intercalates, and indicate a low borate, and high fluoride, intercalate content as compared to anion packing in other graphite intercalation compounds. 相似文献
17.
A novel technique has been developed to synthesize Sn-Fe-Mo-Al2O3, while nanoscale dispersion of a highly active tin phase was finely distributed in a stable inert multi-phase. The precursor was prepared by co-precipitation method with SnCl4, FeCl3, AlCl3 and (NH4)6Mo7O24 as the raw materials. Sn-Fe-Mo-Al2O3 mixture was produced by reducing the precursor with H2. The product was characterized by X-ray diffraction (XRD), ICP and scanning electron microscopy (SEM). The performance of the electrode was investigated. The Sn-Fe-Mo-Al2O3 electrode was found to have an initial charge capacity of over 461 mAh/g, and a reversible volumetric capacity of 2090 mAh/cm3, which is two times larger than that of graphite electrode (800 mAh/cm3). The coulomb efficiency in the first cycle was over 55%, but its cyclability was not improved significantly. In order to enhance the cycle performance, we investigated the anode after heat treated at 270 °C for 12 h. Under the same condition, the first charge-discharge characteristics were almost equivalent to the as-coated anode, and the retention capacity ratio after 20 cycles was improved from 41.1% to 86.5%. The heat-treated Sn-Fe-Mo-Al2O3 electrode exhibited better cycle life. The electrochemical reaction of the Sn-Fe-Mo-Al2O3 electrode with Li may obey the alloying-dealloying mechanism of LixSn(x?4.4) formation in the other tin-based electrodes. 相似文献
18.
Chitosan-montmorillonite nanocomposites were prepared by an ion exchange reaction between water soluble oligomeric chitosan and a Na+-montmorillonite. The chitosan-montmorillonite nanocomposites were rapidly prepared within 1 h due to the high affinity between the chitosan and the montmorillonite clay host. The basal spacings of the composites were in a range of 14.5-19.6 Å depending on the mixing ratio of chitosan to clay. According to the thermogravimetric analysis (TG) and powder X-ray diffraction analysis the thermal stability of chitosan was remarkably improved in the interlayer space due to the strong electrostatic interaction of cationic chitosan molecules with anionic silicate layers. From the antimicrobial activity test it was found that the nanocomposites showed a synergistic effect in the antimicrobial activity against to Escherichia coli and Staphylococcus aureus. 相似文献
19.
I.A. Kartsonakis P. Liatsi D. Bouzarelou 《Journal of Physics and Chemistry of Solids》2008,69(1):214-221
Hollow titania spheres were synthesized using the cationic polystyrene lattices which were prepared by polymerization in suspension of styrene using 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AMPA) as an initiator. These cationic colloidal particles were dispersed in absolute ethanol in the presence of poly(vinylpyrrolidone) (PVP), solution of sodium chloride (NaCl) and mixed with ethanolic solutions of titanium tetraisopropoxide (TTIP). Subsequently, hollow spheres of titania compounds were obtained by calcinations of the so-coated polystyrene lattices at elevated temperature in air. The hollow titania spheres were characterized with scanning electron microscopy (SEM), FT-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Moreover, antibacterial action of illuminated hollow titania spheres on pure culture of Escherichia coli (E. coli) was studied. A decrease of E. coli concentration was observed after illumination of bacteria in the presence of hollow titania spheres. 相似文献
20.
M.E. Mendoza F. Donado J.L. Carrillo 《Journal of Physics and Chemistry of Solids》2003,64(11):2157-2161
Micrometric lamellar ceramic powders of the displacive ferroelectric oxide Bi4Ti3O12 were synthesized by co-precipitation of bismuth nitrate and ammonia titanyl solutions followed by a heat treatment. It was found that a complete thermal decomposition is reached at 1000 °C. Structural and thermal evolution of these ceramic powders were studied by X-ray diffraction, thermogravimetry and differential thermal analysis. The homogeneity in size and morphology of these ferroelectric particles are appropriate to prepare electro-rheological fluids. One of these fluids was prepared by dispersing the powders in silicone oil; the complex cluster structure formed by the particles, under an applied AC electric field, was observed. 相似文献