Synthesis of Carbon Particles using Laser Ablation in Ethanol

AbstractCarbon particles were synthesized via laser ablation of a bulk graphite in ethanol medium using Nd:YAG laser with a wavelength of 1064nm. The target was irradiated by the laser beam with a pulse energy of 3J, a pulse repetition rate of 2Hz, and a pulse duration of 5ms. Effect of using ethanol as a liquid medium for laser ablation on physical, chemical, and optical properties of resulted carbon particles was reported. SEM images presented that a flake-like morphology of graphite in the target has been transformed into a flower-like cluster after the ablation. Raman measurement showed that G peak position of the graphite flakes and that of the synthesized carbon particles were similar, about 1582cm-1, whereas D peak position and its shape of the synthesized particles was different from those of graphite flakes. UV-visible and fluorescent spectrometers were used to investigate absorption and emission characteristics of the particles, respectively. The carbon particles can absorb a light in the UV range and emit a photoluminescence of bright blue-green color

Synthesis, characterization and photocatalytic activity using SiO2-TiO2 nanocomposites under UV light

SiO _2 -TiO _2 nanocomposites were synthesized by the sol-gel method with different SiO _2 contents (0.125, 0.25, 0.50 and 0.75%wt). The characteristics of prepared samples were obtained from x-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), UV–visible spectrophotometer, and Brunauer Emmett and Teller (BET) surface area analyzer. SiO _2 -TiO _2 nanocomposites have higher UV absorption capability and a higher specific surface area compared to pure TiO _2 , resulting in improved dye degradation by photocatalytic activity. The results show that the dye degradation efficiency of 0.5SiO _2 -TiO _2 is higher than pure TiO _2 . It can degrade the dye up to 96.91% within 2 h, while TiO _2 was able to degrade dye at 88.62%