Search

Cadmium zinc aluminum layered double hydroxides (CdZnAl-LDH) were synthesized by urea hydrolysis and co-precipitation method in polyvinyl alcohol (PVA) solution. Cadmium - zinc sulfide (CdZnS) nanoparticles were synthesized on the obtained nanocomposites by the direct sulfidation method both at room temperature (250C) and 400C, and the photocatalytic degradation was studied for the removing of m-cresol from aqueous solutions under visible light. Ultraviolet (UV) spectra, X-ray diffractograms (XRD), Energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectra of the obtained nanocomposites were characterizated and the average size of nanoparticles was determined according to the Scherrer formula. The average crystallite size of CdZnAl-LDH/PVA, CdZnS@CdZnAl-LDH/PVA (250C), and CdZnS@CdZnAl-LDH/PVA (400C) nanocomposites is 14.25 nm, 19.05 nm and 16.5 nm, respectively. It was found that the degree of photocatalytic degradation of m-cresol from water was 18% with CdZnAl-LIH/PVA, 25% with CdZnS@CdZnAl-LIH/PVA (250C), CdZnS@CdZnAl-LIH/PVA (40°C) is 29% under visible light for 3 hours. [ABSTRACT FROM AUTHOR]

In the present investigation, pure and different concentrations (2%, 4%, 6%, 10%) of Ag-doped Co3O4 nanoparticles have been synthesized by the sonochemical method and subsequent calcination at different high temperatures. Structural, optical, morphological properties and elemental composition of synthesized nanoparticles have been characterized using X-ray diffraction, UV–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. According to X-ray diffraction results, no peaks related to silver or silver oxide were observed in the diffractograms of doped samples. Blue shift was observed in the absorption curve of Ag-doped Co3O4 nanoparticles compared to undoped Co3O4 nanoparticles. From transmission electron microscopy measurements, 2%, 4% and 6% Ag-doped Co3O4 nanoparticles thermal annealed at 500 °C exhibit sphere-like and irregularly structured morphology, while 10% Ag-doped Co3O4 nanoparticles have a rhombohedral-like, hexagonal and spherical morphology. The dielectric constant value (ɛʹ) was found to decrease with increasing frequency and it can be explained by Maxwell–Wagner model. The value of the dielectric constant increased with increasing of temperature from 25 to 100 °C and the highest value was observed for Ag0.1Co2.9O4/PVA sample at 100 °C temperature. [ABSTRACT FROM AUTHOR]

Cobalt oxide nanoparticles were synthesized using a facile and convenient sonochemical method, followed by a calcination process. For the synthesis, cobalt nitrate, and sodium borohydride were used as precursors. Polyvinyl alcohol, 3-mercaptopropionic acid, and styrene were used as a stabilizing agent. To identify the structure, optical properties and morphology, the synthesized nanoparticles were characterized using X-ray diffraction, Ultraviolet-Visible Spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. To explain the formation mechanism of cobalt oxide nanoparticles, some investigations were carried out before thermal annealing. In addition, the particle size was tuned by variation of the concentration of 3-mercaptopropionic acid. [ABSTRACT FROM AUTHOR]