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1.
载Ag二氧化钛纳米管的制备及其光催化性能   总被引:9,自引:0,他引:9  
Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticles in 10 mol·L-1NaOHsolution at 110 ℃ for 24 h. The Ag loaded titania nanotubes (Ag/TNTs) were obtained by chemical deposition method with the TNTs suspending in the AgNO3 solution (pH=8) at 50 益. The characterizations of the as-synthesized samples were performed by TEM, EDS, XRD, XPS, and UV-Vis spectra. The photocatalytic performance of the Ag/TNTs was investigated by UV-light induced photocatalytic decomposition of methyl orange(MO). The results showed that the inner/outer diameters of TNTs were about 6/10 nm and the length was several hundred nanometers. Both the shape and the crystalline of the nanotubes were not changed after the modification. The zero oxidation state Ag quantumdots, about 4 nmin diameter, were well dispersed on the external surface of the nanotubes. Ag/TNTs exhibited enhanced absorption at the visible range in the UV-Vis spectra. The Ag nanoparticles were found to significantly enhance the photocatalytic activity of TiO2 nanotubes, and the catalyst system was demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both rutile-phase TiO2 nanoparticles and pure TNTs. After irradiation for 60 min, the decomposition rates of MO solution in rutile-phase TiO2 nanoparticles, TNTs, and Ag/TNTs systemwere 46.8%, 57.2%, and 92.2%, respectively.  相似文献   

2.
纳米氧化镍的制备及其电容特性研究   总被引:4,自引:0,他引:4  
Nano-nickel oxide was synthesized by chemical deposition of nano-nickel hydroxide followed by heat-treatment in air at 300 ℃. The structure of the sample was studied by XRD, TEM, etc. The electrochemical characteristics of the sample were studied by Cyclic Voltammetry and constant current charge/discharge. The results showed that the structure of nickel oxide was cubic and the shape was acicular. The specific capacitance of the nickel oxide was about 130 F·g-1 in the 9.0 mol·L-1 KOH solution. The effects of scan speed, heating temperature and cycling on the specific capacitance were discussed.  相似文献   

3.
PMMA/定向碳纳米管复合材料导电与导热性能的研究   总被引:15,自引:0,他引:15  
徐化明  李聃  梁吉 《无机化学学报》2005,21(9):1353-1356
Methyl Methacrylate(MMA) has been filled in the apertures of aligned carbon nanotubes(ACNTs). Then PMMA/ACNTs composites have been synthesized by in-situ polymerization. The SEM results show that carbon nanotubes are well dispersed and directionally arranged in the composites. The electrical conductivities of the parallel direction (parallel with ACNTs) and perpendicular direction (perpendicular with ACNTs) of composites were respectively tested to be 15 S·cm-1 and 4 S·cm-1, so the composites were conductivity anisotropic. Compared with PMMA, the thermal stable temperature of composites in air was improved by 100 ℃,and the thermal conductivity of composites was 13.64 times of PMMA.  相似文献   

4.
Nanosized nickel oxide was synthesized by immersing the precursor NiHCNFe into 1 mol·L-1 KOH solution to obtain nickel hydroxide (Ni(OH)2) and then annealing in air at 300 ℃. X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests showed the prepared samples were rhombohedral crystalline structure of NiO with uniform grain and with a diameter of about 8 nm. Electrochemical properties of NiO were examined by cyclic voltammetry, ac impedance and galvanostatic charge-discharge tests. The results demonstrated that nickel oxide had a good capacitive behavior and cyclability due to its nanostructure. The highest specific capacitance of nickel oxide was about 303 F·g-1 at a charge/discharge current density of 5 mA·cm-2 in 6 mol·L-1 KOH solution.  相似文献   

5.
超声化学法制备树枝状纳米银的研究   总被引:3,自引:0,他引:3  
Nanostructured silver dendrites were synthesized by using sonochemical method from an aqueous solution of AgNO3 in the presence of isopropanol as reducing agent and polyethylene glycol (PEG) as disperser. The silver nanostructures were characterized by using TEM, XRD and EDS analysis. The effects of reducing agents, dispersers, concentration of AgNO3 on the silver dendrites nanostructures were also invetigated. A well-defined nanostructured silver dendrite was prepared by ultrsonic irradiation of the aqueous solution of 0.04 mol·L-1 silver nitrate, 4.00 mol·L-1 isopropanol and 0.04 mol·L-1 PEG400 for 1 h.  相似文献   

6.
Coating Carbon Nanotubes with Europium Oxide   总被引:4,自引:0,他引:4  
Carbon nanotubes (CNTS) coating with europium oxide by a simple method is reported in this letter for the first time. The CNTS were refluxed in a solution of nitric acid containing europium nitrate, and the pH value was subsequently ajusted with ammonia solution. At last, the mixture was filtered and annealed. The TEM micrograph showed that the CNTS were covered with a uniform thin layer with thickness of about 15 nm. The XRD results revealed that the CNTS were coated with europium oxide.  相似文献   

7.
Lead complex was directly synthesized by electrochemical dissolution of lead in a cell without separating the cathode and anode. The product was characterized by FTIR, Raman spectra and 1H NMR. The xerogel was prepared by a direct sol-gel of the electrolyte solution and then dryness of it. The xerogel was heated at 450 ℃ for 2 h to obtain the nano-PbO powder. FTIR, XRD, and TEM were used to investigate the structure of nano-PbO. The results show that the lead complex is Pb(OEt)2(acac)2, which contains acac- group and could prevent the precursor from hydrolysis and sintering during the calcinations process. The nano-PbO of 20~30 nm was thus obtained in a high purity by drying at 450 ℃.  相似文献   

8.
Rose flower-like SnO hierarchical 3D architectures consisting of well-ordered microsheets were synthesized by a template-free and surfactant-free hydrothermal method based on the reaction between SnCl2 and NaOH in ethanol/water. The ethanol amount is a crucial factor in controlling the size and morphology of the microsheets. Ethanol can accelerate the delamination of the SnO blocks to the microsheets, and the microsheets changed from a quasi square to an octodecahedral shape with the increase of the ethanol ratio. When the volume ratio of ethanol/water is 2:1, the microstructure of SnO presents a rose flower-like hierarchical architecture with a diameter of about 40 μm, which is regularly composed of numerous well-ordered thin microsheets with octodecahedral shape, and the microsheets were formed by countless nanoparticles. A possible growth mechanism of the architectures was proposed. Moreover, SnO2 nanospheres were synthesized by a similar experiment only without NaOH, which showed that NaOH was crucial to the formation of SnOx.  相似文献   

9.
Degradation Action of the Anaerobic Bacteria and Oxygen to the Polymer   总被引:1,自引:0,他引:1  
Oxygen could prohibit anaerobic bacterium in the produced water and degrade the polymer molecular chains. Aiming at problems making up aerobic polymer solution by the produced water in Daqing Oil Field, some evaluations were done on the viscosity characteristics of polymer solution and bactericide in anaerobic and aerobic environments. Reasonable aerobic concentration of the produced water was obtained. The experimental results indicate that the viscosity of polymer solution confected by the produced water in the aerobic environment is higher than that of the polymer solution confected by the produced water in the anaerobic environment, and the reasonable aerobic concentration is about 6 mg•L-1. The bactericide has sterilization ability in anaerobic and aerobic environments, but the sterilization effect is better in the aerobic environment.  相似文献   

10.
In this paper,the TiO2 nanotubes were synthesized by hydrothermal method using a 10 mol/L NaOH aqueous solution at 150℃. The structure of prepared materials was characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM). scanning electron microscope(SEM) and Brunauer-Emmett-Teller(BET).The prepared TiO2 nanotubes were used to prepare thick film gas sensors and the gas sensing properties to various gases were tested.Results show the prepared TiO2 nanotube gas sensors responses to ethanol under dry condition at 450℃.This could be attributed to the fact that it had high porous morphology and a higher pore volume,which can promote the diffusion of ethanol deep inside the films and improve the sensor response. Moreover,the gas sensor made with nanotubes exhibit high selective response towards ethanol gas compared with H2,CO,acetone.  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

15.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

16.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
20.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

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