Characterization of cadmium sulfide nanorods prepared by the solvothermal process

Cadmium sulfide nanorods were successfully prepared from cadmium nitrate tetrahydrate and thiourea in ethylenediamine by 200 °C solvothermal reactions using hydroxyethyl cellulose (HEC) as a capping material. X-ray diffraction (XRD), selected area electron diffraction (SAED), and Raman spectroscopy showed that the products were hexagonal wurtzite CdS with the 1st and 2nd harmonic modes at 303.5 and 593.0 cm^− 1, respectively. The intensity ratios of the 2nd to 1st harmonic modes were increased with their aspect ratios, due to the great strength of exciton-phonon coupling. By using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM) and fast Fourier transformation (FFT), the products were in the shape of nanoparticles in the HEC-free solution, and became nanorods with higher aspect ratios in the HEC-added solutions — especially with longer reaction time. These nanorods were single crystals with growth in the [001] direction.     

Characterization of nano-crystalline LiNiVO4 synthesized by hydrothermal process

LiOH·H₂O, Ni(CH₃COO)₂·4H₂O and NH₄VO₃ were used to synthesize nano-crystalline LiNiVO₄ by hydrothermal process in deionized water at 150 °C for 2 h and subsequent calcination at 300-600 °C for 6 h. By using an X-ray diffractometer (XRD), a transmission electron microscope (TEM) and a selected area electron diffraction (SAED) method, nano-crystalline LiNiVO₄ with inverse spinel structure was detected. The stretching vibration of VO₄ tetrahedrons analyzed by a Fourier transform infrared spectrometer (FTIR) was split into three bands at 661, 746 and 835 cm^− 1, and that analyzed by a Raman spectrometer was detected at 823.9 and 787.7 cm^− 1. The thermogravimetric and differential thermal analyses (TGA and DTA) show two discrete weight losses at 25-117 °C and 117-600 °C and four endothermic peaks at 84, 145, 202 and 372 °C, corresponding to the evaporation of water and the decomposition of inorganic and organic compounds.     

Synthesis and analysis of CuS with different morphologies using cyclic microwave irradiation

Nano- and micro-sized CuS crystals were successfully synthesized from copper and sulfur sources (CuCl₂ ^. 2H₂O, CuBr, Cu(CH₃COO)₂ ^. H₂O, CH₃CSNH₂, NH₂CSNHNH₂ and NH₂CSNH₂) in ethylene glycol assisted by the cyclic irradiation of different microwave powers and prolonged times. By using XRD and SAED, CuS (hcp) was detected. The products characterized using SEM and TEM compose of assemblies of nano-flakes, clusters of nano-particles, nano-fibers, nano-rods and sponge-like structures influenced by the synthesized conditions. Their lattice vibrations are in the same Raman wavenumber at 474 cm⁻¹. Among the different products, the emission peaks are over the range 414–435 nm (2.85–2.99 ev). Reaction evidences of the sources were provided using FTIR. Phase and morphology formations are also proposed on according to the analytical results.