Chemistry Commons^™

Investigations Of The High Pressure Effects On Structural Properties And Co2 Adsorption Performance Of Mofs Using Vibrational Spectroscopy, Shan Jiang

Electronic Thesis and Dissertation Repository

The pre- and post-combustion carbon dioxide capture has drawn much attention in the past few decades owing to the increasing concentration of CO₂ in the atmosphere. Among all the potential solid adsorbents for CO₂ capture, metal-organic frameworks (MOFs) are a promising class of materials due to their large surface areas, high tunability and their high selectivity for gas adsorption applications. It has been widely demonstrated that the application of high external pressure in gigapascal level can substantially tune the structure, pore size and opening of porous material. Consequently, the structural, as well as gas adsorption properties of these …

In Situ High-Pressure Study Of Metal-Organic Frameworks And Their Performance For Co2 Storage Probed By Vibrational Spectroscopy, Yue Hu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are an important class of porous materials, owing to their potential applications in a variety of areas, including gas storage, molecular separations, catalysis, sensors and so on. Most importantly, their extraordinary surface areas, tunable pore properties and potential for industrial scale production have made MOFs a promising material for clean energy applications, such as CO₂ storage. The chemical and mechanical stabilities of MOFs play a crucial role in their CO₂ storage performance, which require extreme loading pressures that are far beyond ambient pressure at times. Application of high external pressure (e.g., in gigapascal range) on …

Optical Properties, Electronic Structures And High Pressure Study Of Nanostructured One Dimensional Titanium Dioxide By Synchrotron Radiation And Spectroscopy, Ankang Zhao

Electronic Thesis and Dissertation Repository

One dimensional (1D) titanium dioxide (TiO₂) nanomaterials have been extensively studied in recent years due to their superior electrical, optical mechanical and chemical properties compared with their bulk counterparts. Two different kinds of 1D TiO₂ nanomaterials, TiO₂ nanowires (TiO₂ NW) and TiO₂ nanotubes (TiO₂ NT), are studied in this thesis by using various techniques.

In one study, TiO₂ NW synthesized by hydrothermal method and a series of calcinated TiO₂ NW were investigated by using absorption near edge structures (XANES), X-ray diffraction (XRD) and X-ray excited optical luminescence (XEOL). It is found …

In Situ High-Pressure Studies Of Energetic Materials By Vibrational Spectroscopy And X-Ray Diffraction, Liang Zhou

Electronic Thesis and Dissertation Repository

Nitrogen-rich materials have been considered as the most promising replacement of traditional energetic materials due to the large energy gap between the different nitrogen allotropes as well as the generation of environmental friendly nitrogen gas as the end-product. As a result, methods of synthesizing the nitrogen-rich materials have received increasing attention. Apart from the traditional chemical synthesis, high-pressure technique had been proved an effective tool to create such kinds of materials. However, several issues still existed concerning the high-pressure synthesis of energetic materials. Therefore, searching for precursors is of great interest. Here we report studies of four promising precursors, 5-aminotetrazole, …

In Situ High-Pressure Studies Of Ammonia Borane Derivatives By Vibrational Spectroscopy, Zhihao Yu

Electronic Thesis and Dissertation Repository

Hydrogen has been regarded as a promising candidate to replace the conventional fossil fuel, and thus attracted enormous research efforts. However, hydrogen storage remains to be a big challenge to its practical applications. Consequently, the investigation of suitable hydrogen storage materials has become a highly active research field. Here we reported the first high pressure studies of three promising hydrogen storage materials, N(CH₃)₃BH₃, NH(CH₃)₂BH₃ and NaNH₂BH₃ by Raman and IR spectroscopy.

First, N(CH₃)₃BH₃ was studied at room temperature and pressures up …