Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Black Tio2 Nts And Zno-Tio2 Nts Heterostructure: Synthesis, Characterization, And Synchrotron-Based Spectroscopy Studies, Lu Yao
Electronic Thesis and Dissertation Repository
The one-dimensional (1D) TiO2 nanotubes (NTs), and their derivatives have been extensively studied due to their potential use in water-splitting, solar cells, and lithium-ion batteries. Since TiO2 has a large band gap (~3.2 eV for anatase), there has been a search for higher photocatalytic efficiency by shifting the band gap into the visible range. This thesis presents a study of black TiO2 NTs and ZnO-TiO2 heterostructures using synchrotron-based X-ray spectroscopy and X-ray diffraction techniques. It involves the transformation from as-prepared TiO2 NTs to black TiO2 NTs via an electrochemical reduction method. ZnO-TiO2 NT …
Synchrotron Study Of Phase Transition And Heterostructures In Metal Oxide Semiconductors, Bingyu Dong
Synchrotron Study Of Phase Transition And Heterostructures In Metal Oxide Semiconductors, Bingyu Dong
Electronic Thesis and Dissertation Repository
Transition metal oxides, including titanium dioxide (TiO2), zinc oxide (ZnO) and Tin dioxide (SnO2) are widely recognized semiconducting photocatalysts. This project engages in a detailed examination of the phase transition of TiO2 and the synthesis of heterostructured metal oxides using an eco-friendly method of ball-milling. A variety of spectroscopy and microscopy techniques have been used to analyze the products. Synchrotron-based techniques: X-ray Absorption near-edge spectroscopy (XANES), X-ray Emission Spectroscopy and X-ray excited optical luminescence (XEOL) can demonstrate the local structure and bonding. The finding highlights a phase transition in TiO2 and the formation of …
Shape-Controlled Nanoparticles As Effective Catalysts For Proton Exchange Membrane (Pem) Fuel Cells, Ali Feizabadi
Shape-Controlled Nanoparticles As Effective Catalysts For Proton Exchange Membrane (Pem) Fuel Cells, Ali Feizabadi
Electronic Thesis and Dissertation Repository
Polymer electrolyte membrane fuel cell (PEMFC), is considered a promising candidate for the next generation power sources in transportation, stationary and portable applications. However, oxygen reduction reaction (ORR), one of the key reactions occurring on PEMFC is kinetically slow; this has limited performance and further advancement in this kind of fuel cells. Thus, improving the PEMFC efficiency requires a thorough understanding of the ORR mechanism on the desired catalyst. To address the above-mentioned demands, the scope of this thesis is focused on the fundamental understanding of facet-controlled nanoparticles, metal-support interactions, and bimetallic platinum catalysts, utilizing synchrotron-based X-ray absorption, X-ray photoelectron …
X-Ray Absorption And Emission Studies Of Anodic Titania Nanostructures, Jun Li
X-Ray Absorption And Emission Studies Of Anodic Titania Nanostructures, Jun Li
Electronic Thesis and Dissertation Repository
One-dimensional (1D) TiO2 nanomaterials with ordered structure have been extensively applied in various fields, such as photocatalysts, solar cells, supercapacitors and rechargeable batteries, due to the unique structural and functional properties compared to the disordered nanoparticulate forms. Nevertheless, intrinsic disadvantages of TiO2, such as its large band gap (~3 eV), fast recombination rate of photoexcited electron–hole pairs and insufficient ionic conductivity, severely limit the development of 1D TiO2 nanomaterials for practical applications. To address the above issues, the scope of this thesis focus on the fundamental understandings of the electronic structure of highly ordered TiO2 …
Mechanism Of Ethanol Partial Oxidation Over Titania Supported Vanadia Catalysts: Geometric And Electronic Structure Consequences On Reaction Kinetics, Dongmin Yun
Electronic Thesis and Dissertation Repository
Supported vanadium oxide catalysts (VOx) are used for a wide range of industrial processes. A significant amount of research has been carried on this specific system with the aim to identify the critical parameters involved in catalytic activity. The results on this relative large body of research indicate that the catalyst support plays a critical role in determining the catalytic activity of vanadia and the use of titanium dioxide as support renders a catalyst with superior activity. Studies on supported vanadia on titanium oxide (VOx/TiO2) have provided an understanding on support interactions that result …