CARBON NANOPARTICLES PREPARED BY LASER ABLATION IN LIQUID ENVIRONMENT

In the present study, carbon nanostructures were synthesized by laser ablation of graphite in deionized water. Q-switched Nd:YAG laser of 1064nm wavelength, 9 ns pulse width, and different laser fluences (3.6, 5.4, 10.6, and 14.6 J/cm(2)) were utilized to irradiate the target. XRD measurements demonstrated the presence of the two carbon phases (002, 111) except for the sample prepared at 3.6 J/cm(2) laser fluence; it showed disappearance of (002) phase. This result can be an indication of changing the phase of carbon nanomaterials when prepared at this fluence. TEM revealed that carbon nanoparticles had a spherical shape and were 10-90nm in size, while nanostructure carbon prepared at 3.6 J/cm(2) has nanosheets 45mm in width and 275mm in length. The absorption of CNPs indicated the appearance of the absorption peak at about 305 nm, which is attributed to the pi-pi* transition of the C = O band. PL emission was decreased at the higher laser fluence (14.6 J/cm(2)) due to the quenching of the carbon nanoparticles luminescence.