Author

Qianqian Liu

Date of Graduation

Summer 2011

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Lifeng Dong

Keywords

carbon nanotube, platinum (Pt), DNA, electroanalytic activity, precursor, TiOΓéé

Subject Categories

Materials Science and Engineering

Abstract

Platinum (Pt) supported on single-walled carbon nanotube (SWCNT) is one of the most efficient catalysts for methanol electroxidation. However, there is lack of a facile and environmental method to synthesize Pt nanoparticles on SWCNT. In the first section, I investigated a novel method to synthesize Pt nanoparticles on SWCNT using DNA molecules as dispersing agent for nanotube uniformly suspended in aqueous solutions and templates for the synthesis of Pt nanoparticles. The morphology of DNA molecules and Pt nanoparticles and their distributions along SWCNT were studied with the use of a number of electron microscopy and microanalysis techniques; electrocatalytic activities of Pt nanoparticles for methanol oxidations were characterized using cyclic voltammetry and A.C. impedance spectroscopy; and interactions among SWCNT, DNA molecules, and Pt nanoparticles were characterized by UV-visible spectroscopy. As a result, I found DNA molecules affect the synthesis of Pt nanoparticles around SWCNT and electrocatalytic activity of Pt nanoparticles supported on SWCNT for methanol oxidations. In the second section, I investigated two approaches for synthesizing carbon nanotube (CNT) coated with TiO2 nanoparticles for solar cell applications. One method used titanium sulfate (Ti (SO4)2) as a reaction precursor, and a second method employed titanium isopropoxide (Ti (OCH (CH3)2)4) as a reaction precursor. My experimental results indicate that without surface functionalization of CNT, nanotube coated with sensitizing TiO2 nanoparticles could be obtained through the selection of desirable precursors and reaction parameters—using Ti (OCH (CH3)2)4 as a reaction precursor .

Copyright

© Qianqian Liu

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