Engineering Commons^™

Simulation And Fabrication Of All Oxide-Based Ito/Tio2/Cuo/Au Heterostructure For Solar Cell Applications, Sajal Islam

MSU Graduate Theses

Oxide heterostructures have drawn great attention lately, due to their environment-friendly properties and potential applications in optoelectronic devices. In this work, a simulation study of a heterojunction solar cell was performed with SCAPS (a solar cell simulator) using TiO2 as an n-type and CuO as a p-type layer. The thickness and the dopant-dependent simulations have shown that the solar cell operates at a maximum efficiency of 19.2% when the thickness of the TiO2/CuO layers is chosen 1.4µm/1.2µm compared to the 11.5% efficiency when FTO is replaced with ITO. An indium-doped tin oxide (ITO) vs fluorine-doped tin oxide (FTO) comparison study …

Photoelectric Properties Of Tio2-Go+Ag Ternary Nanocomposite Material, N. Kh. Ibrayev, A. Zh. Zhumabekov, E. V. Seliverstova

Eurasian Journal of Physics and Functional Materials

A ternary nanocomposite material based on TiO 2 , graphene oxide and core-shell nanostructures of Ag/TiO₂ composition was obtained by a two-step hydrothermal method. The formation of a dual TiO₂-GO nanocomposite was confirmed by Raman spectroscopy data, where the nanocomposite spec- tra contain peaks characteristic of both TiO 2 and graphene oxide. Studies of electrophysical character- istics have shown that the addition of plasmon nanoparticles leads to an improvement in the charge-transfer characteristics of the synthesized material. This is due to the fact that the charge transfer resistance of a ternary nanocomposite material TiO₂-GO-Ag is …

Direct Patterning Of Nature-Inspired Surfaces For Biointerfacial Applications, Feyza Dundar

Doctoral Dissertations

There are three major challenges for the design of patterned surfaces for biointerfacial applications: (i) durability of antibacterial/antifouling mechanisms, (ii) mechanical durability, and (iii) lifetime of the master mold for mass production of patterned surfaces. In this dissertation, we describe our contribution for the development of each of these challenges. The bioinspired surface, Sharklet AF^TM, has been shown to reduce bacterial attachment via a biocide-free structure-property relationship effectively. Unfortunately, the effectiveness of polymer-based sharkskin surfaces is challenged over the long term by both eventual bacteria accumulation and a lack of mechanical durability. To address these common modes of …

Au@Tio2 Nanocomposites Synthesized By X-Ray Radiolysis As Potential Radiosensitizers, Maria C. Molina Higgins

Theses and Dissertations

Radiosensitization is a novel targeted therapy strategy where chemical compounds are being explored to enhance the sensitivity of the tissue to the effects of ionizing radiation. Among the different radiosensitizers alternatives, nanomaterials have shown promising results by enhancing tumor injury through the production of free radicals and reactive oxygen species (ROS). In this work, Gold-supported titania (Au@TiO₂) nanocomposites were synthesized through an innovative strategy using X-ray irradiation, and their potential as radiosensitizers was investigated. Radiosensitization of Au@TiO₂ nanocomposites was assessed by monitoring the decomposition of Methylene Blue (MB) under X-ray irradiation in the presence of the nanomaterial. …

Synthesis Of Crumpled Graphene And Titanium Dioxide Based–Nanomaterials And The Application To Carbon Dioxide Photoreduction, Yao Nie

McKelvey School of Engineering Theses & Dissertations

With the rapid development of the economy, increasing combustion of fossils fuels has caused an increase in the atmospheric carbon dioxide (CO2) level, and has led to global climate change. As a mitigation approach, CO2 capture and conversion (CCC) can not only capture CO2, but also convert it to useable products, such as hydrocarbon fuels. Photocatalytic reduction is an attractive CCC option that directly harnesses inexpensive and abundant solar energy. Titanium dioxide (TiO2) is a widely used semiconductor for photocatalysis, and graphene nanosheets are a promising material for use in fabricating graphene-TiO2 hybridized photocatalysts. To realize the application of these …

Surface Modification Of Electrode Materials For Lithium-Ion Batteries, Biwei Xiao

Electronic Thesis and Dissertation Repository

The development of lithium-ion batteries (LIBs) has been hampered by the intrinsic limitations of the electrode materials. High-performance LIBs demand electrode materials with fast lithium/electron diffusion rate, stable surface chemistry and high specific capacity. Surface modification by atomic layer deposition (ALD) is an essential method to optimize the performance of the electrode materials. The research in this thesis aims at achieving high-performance LIBs via surface modification and understanding the mechanisms via synchrotron radiation.

Firstly, by applying ALD FePO₄ on LiNi_0.5Mn_1.5O₄ (LNMO), we successfully alleviated the electrolyte decomposition under high voltage by using the electrochemically …

Doping Plasmon-Enhanced Tio2 With Zirconia To Improve Solar Energy Harvesting In Dye-Sensitized Solar Cells, Anastasia Pasche

Electronic Thesis and Dissertation Repository

Solar energy is a promising solution towards meeting the world’s ever-growing energy demand. Dye-sensitized solar cells (DSSCs) are hybrid organic-inorganic solar cells with potential for commercial application, but are plagued by inefficiency due to their poor sunlight absorption. Silver nanoparticles have been shown to enhance the absorptive properties of DSSCs, but their plasmonic resonance causes local hot spots, resulting in cell deterioration. This thesis studies the mitigation of thermal energy loss of plasmon-enhanced DSSCs by the co-incorporation of zirconia, a well-known thermostabilizer, into the cell’s photoactive material. TiO2 was also synthesized using green bio-sourced solvents in supercritical CO2 to compare …

Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to identify a new and unique photoactive silicon-related point defect in single crystals of rutile TiO₂. The importance of this defect lies in its assignment to interstitial silicon ions and the unexpected establishment of silicon impurities as a major hole trap in TiO₂. Principal g values of this new S=1/2 center are 1.9159, 1.9377, and 1.9668 with principal axes along the [¯110],[001], and [110] directions, respectively. Hyperfine structure in the EPR spectrum shows the unpaired spin interacting equally with two Ti nuclei and unequally with two Si nuclei. These silicon …

A Novel Silica-Based Nano Pigment As A Titanium Dioxide Replacement, Ryan Stoneburner

Masters Theses

This research focused on the evaluation of a new Silica-based pigment for the replacement of titanium dioxide (TiO₂) in paperboard coatings. The silica-based pigment has shown the ability to be a replacement in terms of functionality and runnability. TiO₂ is currently the highest opacifying pigment used in paper coatings, but it is also the most costly. Finding a less expensive pigment that doesn't reduce effectiveness is critical to reducing the cost of TiO₂ formulations. To evaluate the new pigment, coatings will be applied using a Cylindrical Laboratory Coater (CLC) with varying amounts of TiO₂ and …

Nanostructured Tiox As A Catalyst Support Material For Proton Exchange Membrane Fuel Cells, Richard Phillips

Legacy Theses & Dissertations (2009 - 2024)

Recent interest in the development of new catalyst support materials for proton exchange membrane fuel cells (PEMFCs) has stimulated research into the viability of TiO₂-based support structures. Specifically, substoichiometric TiO₂ (TiO_x) has been reported to exhibit a combination of high conductivity, stability, and corrosion resistance. These properties make TiO_x-based support materials a promising prospect when considering the inferior corrosion resistance of traditional carbon-based supports. This document presents an investigation into the formation of conductive and stable TiO_x thin films employing atomic layer deposition (ALD) and a post deposition oxygen reducing anneal (PDORA). …

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, Processing And Characterization Of Nanocrystalline Titanium Dioxide, Shipeng Qiu

Electronic Theses and Dissertations

Titanium dioxide (TiO2), one of the basic ceramic materials, has found a variety of applications in industry and in our daily life. It has been shown that particle size reduction in this system, especially to nano regime, has the great potential to offer remarkable improvement in physical, mechanical, optical, biological and electrical properties. This thesis reports on the synthesis and characterization of the nanocrystalline TiO2 ceramic in details. The study selected a simple sol-gel synthesis process, which can be easily controlled and reproduced. Titanium tetraisopropoxide, isopropanol and deionized water were used as starting materials. By careful control of relative proportion …