Synthesis and characterization of novel precursors for the deposition of nanoparticle metals on multi-walled carbon nanotubes in supercritical carbon dioxide

Pd(II), W(VI) and Ni(II) metal complexes with ligands derived from fluorous Schiff bases and oximes were synthesized in order to determine their use as precursors in the deposition of metal nanoparticles. Their structures were determined as well as their use in deposition onto multi-walled carbon nanotubes in scCO2. The Schiff base ligands were made by reacting various aniline derivatives with aldehydes. The oxime derivatives were synthesized by reacting various diones with hydroxyl ammonium hydrochloride. In order to increase the solubility of the complexes in scCO2, all of the ligands were synthesized with fluorine, some with long fluorous chains. All ligands were characterized by FT-IR and 1H NMR. The complexes were also characterized via FT-IR and 1H NMR. The metal complexes were qualitatively determined to be soluble in supercritical medium. The synthesized metal complexes were used as precursors for the deposition of the metals onto multiwalled carbon nanotubes, resulting in the synthesis of nano-sized metal catalysts. The synthesized nanocatalyst composites were analyzed by SEM and XRD. The Pd particles ranged from 3.8-13.8nm, the Ni nanoparticles ranged from 1.9-4.0nm, and the W nanoparticles were 0.9-3.0nm.