Nanoscience and Nanotechnology Commons^™

Synthesis And Characterization Of One- And Two-Dimensional Novel Nanomaterials, Yu Zhong

Electronic Thesis and Dissertation Repository

Nanomaterials have attracted extensive interest due to their unique structure and excellent properties compared with their bulk counterparts. To obtain nanodevices with controlled properties, it is prerequisite to synthesize nanostructured materials with designed architecture.

In this work, low (one- and two-) dimensional nanomaterials with controlled structures have been synthesized and characterized based on chemical vapour deposition strategy. Our research targets cover one-dimensinoal hollow, solid, and solid @ hollow heterostructural nanomaterials including carbon nanotubes (CNTs), nitrogen-doped carbon nanotubes (NCNTs), SnO₂ nanowires, Mo doped-SnO₂ nanowires, Sn nanowires encapsulated in CNTs (Sn@CNTs), and two-dimensional Mo₂S₃ nanopetals. Dependence of …

Development Of Novel Nanomaterials For High-Performance And Low-Cost Fuel Cell Applications, Shuhui Sun

Electronic Thesis and Dissertation Repository

Proton exchange membrane fuel cells (PEMFCs) are promising energy converting technologies to generate electricity by mainly using hydrogen as a fuel, producing water as the only exhaust. However, short life-time and high cost of Pt catalyst are the main obstacles for the commercialization of PEMFCs. In the conventional carbon black supported platinum nanoparticle (NP) commercial catalyst, carbon supports are prone to oxidation and corrosion over time that results in Pt NPs migration, coalescence, even detaching from the catalyst support. In addition, Ostwald ripening of the Pt NPs could also occur due to their high surface energy and zero dimensional structural …

Electronic And Magnetic Excitations In Graphene And Magnetic Nano-Ribbons, Maher Zakaria Ahmed Selim

Electronic Thesis and Dissertation Repository

The discovery of graphene - a 2D material with superior physical properties - in 2004 was important for the intensive global research to find alternatives to three-dimensional (3D) semiconductor materials in industry. At the same time there have been exciting advances for 2D magnetic materials on the nanometer scale. The superior properties of graphene are mainly attributed to its crystal structure and its relatively short-range interactions. These properties show that natural and artificial 2D materials are promising for new applications.

In this thesis we have carried out a comprehensive investigation of the effects of the 2D lattice structures, the roles …

Exploring Bacterial Nanowires: From Properties To Functions And Implications, Kar Man Leung

Electronic Thesis and Dissertation Repository

The discovery of electrically conductive bacterial nanowires from a broad range of microbes provides completely new insights into microbial physiology. Shewanella oneidensis strain MR-1, a dissimilatory metal-reducing bacterium, produces extracellular bacterial nanowires up to tens of micrometers long, with a lateral dimension of ~10 nm. The Shewanella bacterial nanowires are efficient electrical conductors as revealed by scanning probe techniques such as CP-AFM and STM.

Direct electrical transport measurements along Shewanella nanowires reveal a measured nanowire resistivity on the order of 1 Ω∙cm. With electron transport rates up to 10⁹/s at 100 mV, bacterial nanowires can serve as a …

On Developing Novel Energy-Relates Nanostructured Materials By Atomic Layer Deposition, Xiangbo Meng

Electronic Thesis and Dissertation Repository

ABSTRACT

This thesis presents the fabrication of a series of novel nanostructured materials using atomic layer deposition (ALD). In contrast to traditional methods including chemical vapor deposition (CVD), physical vapor deposition (PVD), and solution-based processes, ALD benefits the synthesis processes of nanostructures with many unrivalled advantages such as atomic-scale control, low temperature, excellent uniformity and conformality. Depending on the employed precursors, substrates, and temperatures, the ALD processes exhibited different characteristics. In particular, ALD has capabilities in fine-tuning compositions and structural phases. In return, the synthesis and the resultant nanostructured materials show many novelties.

This thesis covers ALD processes of four …

Synthesis Of One-Dimensional And Two-Dimensional Carbon Based Nanomaterials, Mihnea Ioan Ionescu

Electronic Thesis and Dissertation Repository

Particular physical and chemical properties of carbon based nanomaterials (CBNs) have promised and exhibited great applications in manufacturing various nanodevices such as electron field emitters, sensors, one-dimensional conductors, supercapacitors, reinforcing fibres, hydrogen storage devices, and catalyst support for fuel cells electrodes. Despite these amazing technical progresses, many challenges still remain in the development of synthesis methods suitable for commercial applications and fabricating novel functional nanostructures with complex architecture.

In this Ph.D. thesis, one-dimensional (1D), two-dimensional (2D) carbon nanostructures, and 1D/2D hybrid of carbon nanostructures have been synthesized using various chemical vapour deposition (CVD) methods. The objective of this work is …