Effect of C/H and C/O ratios on the arc discharge synthesis of titanium carbide nanoparticles in organic liquids

TiC nanoparticles were synthesized by submerged direct current (DC) arc discharge in liquid. Synthesis process was carried out in methanol, ethanol and acetone under inert atmosphere by applying 40A between two pure titanium electrodes with vertical configuration. X-ray diffraction, field emission scanning electron microscopy and UV-visible spectroscopy were used for characterization of nanoparticles. In addition, plasma species were characterized via optical emission spectroscopy (OES). According to the obtained results, nanoparticle shape is spherical, and average particle size of nanoparticles is 28, 45 and 38nm in methanol, ethanol and acetone, respectively. Although composition of nanoparticles in ethanol and acetone is single-phase of TiC, the presence of around 30% of rutile phase of TiO2 was observed in methanol. According to the OES observation, TiC nanoparticle formation mechanisms are discussed based on the decomposition of organic liquids in arc discharge zone, formation of some carbon species and reaction of this carbon-containing species with Ti species in plasma. In addition, C/H and C/O ratios play a critical role in formation and dominant phase of final product. These results demonstrate a simple and flexible method for rapid mass production of TiC and other refractory metal carbides nanoparticles in an appropriate organic liquid.