Chemical Structure of TiO Organometallic Particles Obtained by Plasma

This work presents a study about the chemical structure of titanium oxide (TiO) particles synthesized by plasmas using titanium tetrapropoxide, Ti(-O-CH2-CH2-CH3)4. In plasmas, practically all chemical bonds are susceptible to participate in the reactions producing different results than those obtained by the traditional chemical routes. The particles obtained this way are semispheres and fibers grouped in random and layered structures in the 120-500 nm interval and mean diameter of 86.4 nm (fibers) and 308.6 nm (semispheres). The analysis of the resulting TiO structure was performed by IR and XPS finding that the main chemical state of Ti in these conditions was O2-Ti-O2 (Ti surrounded by O) which is part of the precursor structure, however, in O, the main chemical state was Ti-O-Ti formed with the rupture of the pre- cursor Ti-O-C bonds. These last bonds reduce the conjugation between the structure of both elements, O2-Ti-O2 and Ti-O-Ti, to produce organometallic compounds. Other chemical states appeared showing consecutive dehydrogenation steps during the synthesis with the formation of multiple bonds as a consequence of the continuous collisions in the plasma. These results allow us to follow the chemical reactions promoted by this kind of plasmas to produce TiO nanoparticles which are essentially conformed of intensive dehydrogenation.