Inorganic Chemistry Commons^™

Nanomaterial Composites Based On Potassium Hexaniobate, Perovskites, And Iron Triazole Spin Crossover Complexes, Alexis A. Blanco

University of New Orleans Theses and Dissertations

Development of novel materials with sought after properties has been the forefront in the field of nanomaterials. Hybrid nanomaterial architectures, or nanocomposites, is an important subgroup within the material chemistry umbrella. One such example of nanocomposite systems is peapod-like structures that are composed of 0D nanoparticles (“peas”) and 2D nanosheets (“pods”). Nanopeapods may display unique properties that were not attainable within individual components. BaTiO₃ nanoparticles can be produced using solvothermal methods (20 h) in the presence of Ba(NO₃)₂, titanium (IV) butoxide, and oleic acid as the surfactant. Synthesis parameters were modified to allow for both …

Design And Synthesis Of Novel No-Drug Hybrid Compound And Green Catalytic Activity Evaluation Of Synthesized Silver Nanoparticles-Halloysite Nanocomposite, Majed Abdullah Bajaber

University of New Orleans Theses and Dissertations

Acetaminophen is a well-known analgesic that can manage pain and reduce fever. SCP-1 is a derivative of acetaminophen that showed significantly reduced hepatotoxicity and nephrotoxicity comparative to acetaminophen. Nitric oxides have been well known to play a key role in a wide variety of physiological and pathophysiological important processes. It was therefore of interest to synthesize a nitric oxide donor linked to SCP-1 that could have enhanced analgesic and antipyretic activity. A furoxan CAS 1609 as NO-donor was synthesized and linked to SCP-1 successfully. The furoxan CAS 1609 was initially synthesized from tetronic acid to give 1,2- dioxime in 86 …

Platinum@Hexaniobate Nanopeapods: Sensitized Composite Architectures For Photocatalytic Hydrogen Evolution Under Visible Light Irradiation, Clare Davis-Wheeler Chin

University of New Orleans Theses and Dissertations

Hydrogen fuel is one of the most important areas of research in the field of renewable energy development and production. Hydrogen gas can be generated by fuel cells, water electrolyzers, and heterogeneous nanoscale catalysts. It can be burned to directly release chemical energy or condensed for storage and transport, providing fuel for combustion devices or storing excess energy generated by renewable sources such as wind turbines and concentrated solar power assemblies. While platinum is the most active catalyst for hydrogen reduction, its high cost significantly deters its utilization in advanced photocatalytic materials. One approach to mitigating this expense is optimizing …

Fabrication And Characterization Of Intricate Nanostructures, Treva T. Brown

University of New Orleans Theses and Dissertations

Encapsulation of nanoparticles within hexaniobate nanoscrolls presents interesting advances in the formation of nanocomposites exhibiting unique multi-dimensional properties. Building upon previous successes, facile yet versatile wet-chemical and microwave-irradiation synthetic protocols for the fabrication of a series of hexaniobate composites are presented herein. Solvothermal and, more recently, microwave-assisted methods have been developed that allow for the fabrication of peapod-like structures. During solvothermal treatment, exfoliated hexaniobate nanosheets scroll around highly ordered chains of preformed nanoparticles (NPs) to produce nanopeapods (NPPs). This approach offers versatility and high yields, in addition to the potential for advanced functional device fabrication.

For the characterization of these …

Microwave-Assisted Topochemical Manipulation Of Layered Oxide Perovskites: From Inorganic Layered Oxides To Inorganic-Organic Hybrid Perovskites And Functionalized Metal-Oxide Nanosheets, Sara Akbarian-Tefaghi

University of New Orleans Theses and Dissertations

Developing new materials with desired properties is a vital component of emerging technologies. Functional hybrid compounds make an important class of advanced materials that let us synergistically utilize the key features of the organic and inorganic counterparts in a single composite, providing a very strong tool to develop new materials with ”engineered” properties. The research presented here, summarizes efforts in the development of facile and efficient methods for the fabrication of three- and two-dimensional inorganic-organic hybrids based on layered oxide perovskites. Microwave radiation was exploited to rapidly fabricate and modify new and known materials. Despite the extensive utilization of microwaves …

Design And Fabrication Of Nanostructures For The Enhancement Of Photovoltaic Devices, Richard M. Prevost Iii

University of New Orleans Theses and Dissertations

In 2012 the net world electricity generation was 21.56 trillion kilowatt hours. Photovoltaics only accounted for only 0.1 trillion kilowatt hours, less than 1 % of the total power. Recently there has been a push to convert more energy production to renewable sources. In recent years a great deal of interest has been shown for dye sensitized solar cells. These devices use inexpensive materials and have reported efficiencies approaching 12% in the lab. Here methods have been studied to improve upon these, and other, devices. Different approaches for the addition of gold nanoparticles to TiO₂ films were studied. These …

Engineering Nanoarchitectures From Nanosheets, Nanoscrolls, And Nanoparticles, Taha Rostamzadeh

University of New Orleans Theses and Dissertations

The ability to encapsulate/insert different kinds of nanoparticles (NPs) in scrolled nanosheets (NSs) may lead to the formation of new nanocomposite materials that yield novel properties. These nanostructures resemble “peapods” that consist of NPs chains (“peas”) located in a hollow space of desired nanoscrolls (“pods”). Depending on different combinations of “peas” and “pods” diverse families of nanopeapods (NPPs) can be synthesized which may exhibit interesting properties not accessible from the individual components. Though there exist various synthetic methods for the formation of NPPs, more development in terms of simplicity, flexibility, and productivity of synthetic approaches are needed so that different …

Synthesis And Topochemical Manipulation Of New Layered Perovskites, Lea Gustin

University of New Orleans Theses and Dissertations

Metastable layered perovskites containing interlayer transition metals can readily be obtained by simple ion exchange reactions on receptive hosts, such as those of the Dion-Jacobson and Ruddlesden-Popper structure types. In this work, we focused on adding to the library of layered perovskites by not only creating new compounds, but by also showing their ability to be further manipulated, and by studying the stability of the series through thermal behavior studies.

The reactions with transition metal halides are particularly interesting since they often lead to novel architectures and magnetic behavior. On subsequent heat treatment, these exchange products typically decompose to thermodynamically …

Hexaniobate Nanopeapods: In Situ Deposition Of Magnetic-Noble Metal Nanoparticles Inside Preformed Nanoscrolls, Sarah P. Gauthier

University of New Orleans Theses and Dissertations

An in situ deposition procedure was developed for the nanopeapod (NPP) formation of NiAu nanoparticles inside preformed acid-exchanged hexaniobate nanoscrolls (HNB). Metal salt precursors of Ni(acac)₂ and HAuCl₄∙3H₂O were reduced in solution under mild synthetic conditions in the presence of the preformed acid-exchanged hexaniobate nanoscrolls. Two of the surfactants used for the formation of the nanoparticles were oleylamine and triphenylphosphine oxide (TTPO). Reaction conditions were studied and modified to produce well-defined NiAu@HNB NPP systems, with monodispersed particles evenly filling and orienting within the nanoscrolls. The synthetic parameters studied were both time and temperature, with the …

New Dion-Jacobson And Ruddlesden- Popper Layered Perovskites Prepared By Topochemical Methods, Dariush Montasserasadi

University of New Orleans Theses and Dissertations

Layered perovskites can be classified in three major groups: Dion-Jacobson AA′_n-1B_nO_3n+1, Ruddlesden-Popper A₂A′_n-1B_nO_3n+1,and Aurivillius phase (Bi₂O₂)A′_n-1B_nO_3n+1. (A: Alkali metal, Alkali-earth metal; A′: Lanthanides and Bi; B: Ti, Nb, Ta; n: thickness of slabs). For more than two decades researchers have shown much interest in this series because of their magnetic and electrical properties. Tuning synthesis parameters such as temperature, time, and host structure can be used to direct such properties. Low temperature synthetic methods (topochemical methods) allow …

New Metal-Nhc Complexes: Synthesis, Characterization, And Uses, Roy A. Kelly Iii

University of New Orleans Theses and Dissertations

N-Heterocyclic Carbenes (NHC) present a viable alternative to traditional phosphine ligands in a variety of organometallic mediated catalytic reactions. Singlet ground-state carbenes are stabilized by the push-pull presence of two adjacent nitrogen atoms in an imidizolium 5-membered ring, allowing neutral electron donor properties. The ability to synthesize a variety of NHC ligands with differing steric and electronic properties is possible by changing the sustiuents on the nitrogen atoms of the imidizolium. Tunable characteristics and enhanced chemical and thermal stability give NHC’s an advantage over phosphines in many catalytic systems.

This dissertation focuses on the use N-Hetercyclic Carbenes in a variety …

High Yield Solvothermal Synthesis Of Hexaniobate Based Nanocomposites Via The Capture Of Preformed Nanoparticles In Scrolled Nanosheets, Shivaprasad Reddy Adireddy

University of New Orleans Theses and Dissertations

The ability to encapsulate linear nanoparticle (NP) chains in scrolled nanosheets is an important advance in the formation of nanocomposites.These nanopeapods (NPPs) exhibit interesting properties that may not be achieved by individual entities. Consequently, to fully exploit the potential of NPPs, the fabrication of NPPs must focus on producing composites with unique combinations of morphologically uniform nanomaterials. Various methods can produce NPPs, but expanding these methods to a wide variety of material combinations can be difficult. Recent work in our group has resulted in the in situ formation of peapod-like structures based on chains of cobalt NPs. Building on this …

Nanomaterials For Biological Applications: Drug Delivery And Bio-Sensing, Hui Ma

University of New Orleans Theses and Dissertations

The idea of utilizing nanomaterials in bio-related applications has been extensively practiced during the recent decades. Magnetic nanoparticles (MPs), especially superparamagnetic iron oxide nanoparticles have been demonstrated as promising candidates for biomedicine. A protective coating process with biocompatible materials is commonly performed on MPs to further enhance their colloidal and chemical stability in the physiological environment. Mesoporous hollow silica is another class of important nanomaterials that are extensively studied in drug delivery area for their ability to carry significant amount of guest molecules and release in a controlled manner.

In this study, different synthetic approaches that are able to produce …

Surface Functionalized Water-Dispersible Magnetite Nanoparticles: Preparation, Characterization And The Studies Of Their Bioapplications, Haiou Qu

University of New Orleans Theses and Dissertations

Iron oxide magnetic nanoparticle synthesis and their surface functionalization hold a crucial position in the design and fabrication of functional materials for a variety of biomedical applications. Non-uniform nanoparticles with poor crystallinity, prepared by conventional methods, have only limited value in biological areas. Large scale synthesis methods that are able to produce high quality, mono-dispersed iron oxide nanoparticles using low cost and environment friendly chemicals are highly desirable. Following synthesis, appropriate surface functionalization is necessary to direct the dispersibility of nanoparticles in aqueous solution in order to provide them with acceptable colloidal stability against the ion strength and many biomolecules …

Investigating The Electron Transport And Light Scattering Enhancement In Radial Core-Shell Metal-Metal Oxide Novel 3d Nanoarchitectures For Dye Sensitized Solar Cells, Gayatri Sahu

University of New Orleans Theses and Dissertations

Dye-sensitized solar cells (DSSCs) have attained considerable attention during the last decade because of the potential of becoming a low cost alternative to silicon based solar cells. Electron transport is one of the prominent processes in the cell and it is further a complex process because the transport medium is a mesoporous film. The gaps in the pores are completely filled by an electrolyte with high ionic strength, resulting in electron-ion interactions. Therefore, the electron transport in these so called state-of-the-art systems has a practical limit because of the low electron diffusion coefficient (D_n) in this mesoporous film …