BaMoO4 and BaWO4 nanocrystals were synthesized from Ba(NO3)2 and Na2MeO4 (Me=Mo and W) solutions using 50% of 600 W microwave irradiation for 20 min. The products were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and photoluminescence (PL) spectrophotometry. They show that the products are good dispersed nanocrystals (poly-nanocrystals) of single-phase scheelite tetragonal structure with the vibration modes corresponding to the molybdate and tungstate compounds. Their photoluminescence was detected at 415 and 392 nm for BaMoO4 and BaWO4, respectively. 相似文献
Ag nanoparticles supported on the surface of three-dimensional (3D) flower-like ZnO nanostructure were synthesized by a microwave-assisted solution method. The obtained products were characterized by X-ray diffraction analysis, field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, Raman spectrophotometry, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The analytical results confirmed homogeneously distributed Ag nanoparticles supported on the surface of flower-like ZnO nanostructure. The photocatalytic effect of the heterostructure Ag/ZnO nanocomposites was investigated using photodegradation under ultraviolet (UV) light of methylene blue as model dye. The heterostructure Ag/ZnO nanocomposites exhibited much higher photocatalytic activity than pure ZnO flowers. The improved photocatalytic properties are attributed to formation of a Schottky barrier at the metal–semiconductor interface of the Ag/ZnO nanocomposites. 相似文献
Bi2MoO6 nanoplates modified with intermetallic AgPd nanoparticles synthesized by photoreduction deposition method were used for visible-light-driven photodegradation of rhodamine B. The as-synthesized AgPd/Bi2MoO6 nanocomposites were identified by XRD. The 2θ diffraction angle of the (111) plane of pure metallic cubic Ag at 38.11° of heterostructure 10% Ag/Bi2MoO6 nanocomposites shifted to a higher diffraction angle at 38.17° of heterostructure 10% Ag0.7Pd0.3/Bi2MoO6 nanocomposites. TEM images of the as-synthesized nanocomposites showed good metallic Ag and intermetallic AgPd nanoparticles with particle size of 10–12 nm which were fully supported on top of Bi2MoO6 nanoplates. Bi2MoO6 nanoplates deposited with intermetallic AgPd nanoparticles show significant photocatalytic activity better than Ag/Bi2MoO6 and Bi2MoO6 due to the formation of AgPd/Bi2MoO6 Schottky barrier.
Molybdenum trioxide (MoO3) nanowire with unprecedentedly high aspect ratios (>200) and good crystallinity was prepared via decomposition of (NH4)6Mo7O24·4H2O under a microwave-assisted hydrothermal (MH) process. The nanowire was orthorhombic MoO3 with 50 nm in diameter and 10–12 μm in length. The conventional hydrothermal (CH) reaction required higher temperature and longer reaction times to produce one-dimensional MoO3, yet its quality was lower. In the electrochemical hydrogen evolution reaction in a H2SO4 solution, MoO3 nanowire from MH process showed much higher electrocatalytic activity than MoO3 prepared from CH method and commercial bulk MoO3 particles. The facile vectorial electron transport along the nanowire axis was considered to be responsible for the excellent electrocatalytic activity of the MH–MoO3 nanowire. 相似文献
Orthorhombic molybdenum trioxide (α-MoO3) nanobelts have been successfully synthesized by hydrothermal method at 180°C for 20 h. The prepared α-MoO3 samples were investigated by X-ray diffraction, Fourier transform IR spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy methods. It was found that α-MoO3 nanobelts grow along the c-axis, with ±(100) top or bottom surfaces and ±(010) side surfaces. The prepared α-MoO3 nanobelts were used as cathode materials for Li-ion batteries. They exhibit specific capacity of 1340 and 1250 mA h g–1 at a current density of 100 and 400 mA/g, respectively. 相似文献
Orthorhombic MoO3 and W-doped MoO3 nanobelts were successfully synthesized by a hydrothermal method. The effect of W dopant on the photocatalytic performance of W-doped MoO3 nanobelts was studied. The phase, morphology, and oxidation state of the products were characterized by X-ray diffraction analysis, Fourier-transform infrared and Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. In this research, MoO3 and W-doped MoO3 exhibited the same phase and morphology of orthorhombic nanobelts with growth along the [001] direction, including detection of Mo6+, O2?, and W6+ in the 3 mol% W-doped MoO3 sample. The photocatalytic performance of the as-synthesized MoO3 and W-doped MoO3 nanobelts was monitored through photodegradation of methylene blue (MB) under visible radiation. W-doped MoO3 nanobelts showed better photocatalytic performance than pure MoO3. The 3 mol% W-doped MoO3 photocatalyst exhibited very good visible-light-driven activity for photodegradation of MB, as high as 99 % within 60 min. 相似文献
Journal of Nanoparticle Research - SrMoO4 and SrWO4 nanocrystals have been synthesized using Sr(NO3)2 and Na2MeO4 (Me = Mo and W) in ethylene glycol by a microwave irradiation... 相似文献
CdS nanorods were solvothermally produced from Cd(CH3COO)2 and S powder using ethylenediamine (en) as a solvent and hydroxyethyl cellulose (HEC) as a template. The phase with hexagonal structure was detected using XRD and SAED, which is in perfect accordance with the results obtained by simulation. SEM, TEM and HRTEM revealed the development of nanorods with a number of atoms arranged in crystal lattices. When the appropriate amount of HEC was used, the longest nanorods, with preferential growth in the [0 0 1] direction, were produced. Raman spectra showed the fundamental and overtone modes at the same wavenumbers of 301 and 599 cm−1, respectively. Their relative intensities at each temperature were strongly influenced by the anisotropic geometry of the products. Photoluminescence caused by electron-hole recombination was detected at 470 nm, and by surface trapping induced emission at 575 nm. The formation mechanism of CdS nanorods was also proposed based on the experimental results. 相似文献
AWO4 (A = Ca, Sr) was prepared from metal salts [Ca(NO3)2·4H2O or Sr(NO3)2], Na2WO4·2H2O and different moles of cetyltrimethylammonium bromide (CTAB) in water by cyclic microwave irradiation. The structure of AWO4 was characterized by X-ray diffraction (XRD) and selected area electron diffraction (SAED). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed the presence of nanoparticles in clusters with different morphologies; spheres, peaches with notches, dumb-bells and bundles, influenced by CTAB. Six Raman vibrational peaks of scheelite structure were detected at 908, 835, 793, 399, 332 and 210 cm−1 for CaWO4 and 917, 833, 795, 372, 336 and 192 cm−1 for SrWO4, which are assigned as ν1(Ag), ν3(Bg), ν3(Eg), ν4(Bg), ν2(Ag) and νf.r.(Ag), respectively. Fourier transform infrared (FTIR) spectra provided the evidence of W-O stretching vibration in [WO4]2− tetrahedrons at 793 cm−1 for CaWO4 and 807 cm−1 for SrWO4. The peaks of photoluminescence (PL) spectra were at 428-434 nm for CaWO4, and 447-451 nm for SrWO4. 相似文献