Characterization of micro-crystalline lead tungstate with different morphologies produced by the sonochemical process

Micro-crystalline PbWO₄ was sonochemically produced using Pb(CH₃COO)₂ · 3H₂O and Na₂WO₄ · 2H₂O in aqueous solutions with and without anionic surfactant (sodium dodecyl sulphate or sodium lauryl sulphate). The product morphologies were influenced by the pH values and the surfactant. Micro-crystalline PbWO₄ composing of Pb, W and O, and W-O stretching vibration band of WO₄ tetrahedrons were detected using XRD, SEM, EDX, TEM, SAED and FTIR. Photoluminescent intensities, caused by the electronic transition from ¹T₂ to ¹A₁ states, shown to increase with the increase in the pH values of the solutions.     

Analysis of lead molybdate and lead tungstate synthesized by a sonochemical method

Lead molybdate and lead tungstate nanoparticles were successfully synthesized by a sonochemical method for 1 h. XRD patterns showed the body-centered tetragonal structures of PbMoO₄ and PbWO₄, and were in accordance with those of the simulation and JCPDS software. Calculated lattice parameters are a = b = 5.4233 Å and c = 12.1253 Å for PbMoO₄, and 5.4570 Å and 12.0995 Å for PbWO₄. They are in accordance with those of the corresponding JCPDS software. TEM images show that the particles were 29.09 ± 5.22 nm and 21.05 ± 2.68 nm for PbMoO₄ and PbWO₄, respectively. Raman and FTIR vibrations were investigated to identify a definite existence of the structures.     

Microwave-assisted synthesis and optical property of CdMoO4 nanoparticles

Microwave-assisted synthesis is a novel method used to synthesize CdMoO₄ nanoparticles in propylene glycol. The effects of reaction time and microwave power on phase, morphologies, and optical properties of CdMoO₄ nanoparticles were studied, using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and UV-visible spectroscopy. The present analyses proved that these crystalline powders were scheelite-type tetragonal structured CdMoO₄, with the crystallite size of 14-20 nm, and 4.51-4.73 eV band gaps, controlled by the synthetic conditions.     

Microwave-assisted hydrothermal synthesis of BiOCl/Bi2WO6 nanocomposites for the enhancement of photocatalytic efficiency

Research on Chemical Intermediates - In this research, BiOCl/Bi2WO6 nanocomposites were successfully synthesized by a microwave-assisted hydrothermal method. Phase, morphology and optical...     

Surface modification of TiAl alloy via current heating technique

Surface of Ti-52 at% Al alloy was modified via current heating technique. The Ti-52 at% Al alloy with 20 mm diameter × 1.5 mm thick disks was placed in graphitic powder in a glass tube and pressed against it. During the coating process, the direct current was applied across the samples at electrical power of 100-200 W for 10 min. By using X-ray diffraction (XRD), TiC was detected on the alloy treated at 180 W and above. Scanning electron microscopy (SEM) micrographs show the different morphologies, after treatment under different conditions. Energy dispersive X-ray spectroscopy (EDS), SEM and hardness tester show that the carbon concentration, particle size, void size and the hardness of the alloy were increased with the increasing of the applying electrical power, due to the formation of the carbide on the alloy surface.     

Characterization of PbS with different morphologies produced using a cyclic microwave radiation

PbS was produced from different lead (Pb(CH₃COO)₂·H₂O, PbCl₂·2.5H₂O, Pb(NO₃)₂) and sulfur (CH₃CSNH₂, CH₅N₃S, NH₂CSNH₂) sources in propylene glycol using a cyclic microwave radiation at different powers and prolonged times. PbS (cubic) was detected using X-ray diffraction (XRD) and selected area electron diffraction (SAED) techniques. The interpreted and simulated patterns are in good accord. Raman spectrometer revealed the presence of vibrations at 138, 273 and 439 cm⁻¹. Different morphologies (nano-sized particles, hexapods, cubes, ferns and magic squares) were characterized using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The product morphologies were influenced by the starting agents, microwave powers and prolonged times.     

Synthesis,Characterization and Optical Properties of BaMoO<Subscript>4</Subscript> Synthesized by Microwave Induced Plasma Method

BaMoO₄ crystals were synthesized by a 900 W microwave induced plasma process (MIP) for 40, 60, 120 and 140 min. Phase, morphology, vibrational mode and energy gap were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy. In this research, the phase and morphology of product were influenced by microwave heating time. The sample processed for 140 min shows spherical particles tetragonal BaMoO₄ phase with size of 200–700 nm in diameter. BaMoO₄ with band gap of 3.35 eV shows a blue emission wavelength at 440 nm.     

Barium molybdate and barium tungstate nanocrystals synthesized by a cyclic microwave irradiation

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.     

Synthesis,Characterization and Antibacterial Activity of BiVO4 Microstructure

Russian Journal of Physical Chemistry A - Hyperbranched BiVO4 microstructure were successfully synthesized by a hydrothermal method. Upon characterization the products by X-ray diffraction (XRD),...