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Nanostructures by gas-phase reactions: growth and applications

Carney, Carmen M.

Abstract Details

2006, Doctor of Philosophy, Ohio State University, Materials Science and Engineering.
Gas-phase reactions between H 2and SnO 2surfaces led to novel nanostructures. Nanosheets of SnO 2were produced by a gas-phase reaction of solid SnO 2sintered disks in a reducing atmosphere between 700 and 800 degrees Celsius. The surface morphology was controlled by varying the reaction time and partial pressure of oxygen. It was found that SnO 2was etched by a reaction between H 2and lattice oxygen and a loss of SnO to the vapor phase. Single-crystalline nanofibers of SnO 2were synthesized by a gas-phase reaction of solid SnO 2sintered disks in a reducing atmosphere between 650 and 750 degrees Celsius. The resulting nanostructures grew on regions of the sample that were coated with gold, which acted as a collector of SnO vapor. The nanofiber length was controlled by varying the reaction time and by the sintering agent used to densify the SnO 2. SnO 2thin films were manufactured using DC reactive magnetron sputtering from a tin target in an Ar/O 2atmosphere. After exposure to H 2gas at temperatures between 600 and 680 degrees Celsius, nanofibers were grown on the surface with the aid of gold particles. The nanofiber growth was controlled by varying the reaction time and the orientation of the SnO 2films. The gold was shown to be necessary for both initiation and continuation of growth. Sensing tests were conducted with pure TiO 2and mixed oxide samples of TiO 2and SnO 2sintered samples having different surface areas. Nanostructures of solid solutions and spinodally decomposed samples of mixed oxides of SnO 2and TiO 2were compared to the oriented nanofibers formed in pure TiO 2created by the same heat treatment. Thin films with SnO 2nanofibers were also tested for their sensing response to H 2. Comparisons between the sensing characteristics of the samples were made to determine that those samples with high surface areas and those with a gold coating were more sensitive to H 2in the presence of O 2.
Sheikh Akbar (Advisor)
222 p.

Recommended Citations

Citations

  • Carney, C. M. (2006). Nanostructures by gas-phase reactions: growth and applications [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1163772131

    APA Style (7th edition)

  • Carney, Carmen. Nanostructures by gas-phase reactions: growth and applications. 2006. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1163772131.

    MLA Style (8th edition)

  • Carney, Carmen. "Nanostructures by gas-phase reactions: growth and applications." Doctoral dissertation, Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1163772131

    Chicago Manual of Style (17th edition)