Synthesis, Modifications, and Applications of Porous Nanostructures
| dc.contributor.advisor | Martí, Angel A | en_US |
| dc.creator | Ling, Kexin | en_US |
| dc.date.accessioned | 2022-12-21T20:13:58Z | en_US |
| dc.date.available | 2022-12-21T20:13:58Z | en_US |
| dc.date.created | 2022-12 | en_US |
| dc.date.issued | 2022-11-22 | en_US |
| dc.date.submitted | December 2022 | en_US |
| dc.date.updated | 2022-12-21T20:13:59Z | en_US |
| dc.description.abstract | Porous materials, with their high surface areas, controllable structures, and tunable pore sizes, comprise an interdisciplinary research field in focus today, and one that is developing rapidly. Various porous materials have been adopted for different applications, including adsorption, separation, catalysis, energy conservation, sensing, and drug delivery. Thus, there is an ever-increasing demand for synthesizing porous materials with desired structures and compositions to meet specific requirements. In this thesis, three distinct porous materials will be covered: iron oxide/carbon composite, rhenium carbonyl complex incorporated UiO-67 MOFs, and fluorinated boron nitride nanotubes. Chapter 1 generally summarized the fundamentals about synthetic methods and structural properties of porous materials. The development of the three materials covered in this thesis will also be introduced in detail. Activated carbon is one of the most ever studied porous materials. Its composites with metal oxides show potential for desulfurization. In Chapter 2, we explored the synergic effects in composites of iron oxide (Fe2O3) and oxygenated porous carbon (OPC) for the removal of H2S at room temperature. Two types of Fe2O3-OPC composite samples were prepared: physically mixed (PM) and chemically mixed (CM). The two types of composites were tested for H2S uptake performance at ambient conditions, and a systematic study of the synergic effects of Fe2O3 and OPC was performed. Thorough characterization and analysis were used to reveal detailed structural and compositional properties of these samples. The CM sample with the best uptake capacity was also tested further for the desulfurization rate and the mechanism of action. The PM samples showed a lower H2S uptake capacity within 24 h compared to the theoretical value for the Fe2O3 and OPC working independently, indicating a negative synergic effect. The CM samples reached a maximum uptake capacity higher than the components working independently and importantly an increased rate of H2S uptake, which indicates positive synergy, showing potential in applications where rapid adsorption is required. Directly coordinating transition metal catalysts to the linkers of stable metal organic frameworks (MOFs) is a sleek solution to increasing the longevity of the catalyst. In Chapter 3, Re(bpydc)(CO)3Cl (bpydc = 2,2’-bipyridine-5,5’-dicarboxylic acid) doped zirconium-based MOFs (Re-UiO-67) were synthesized. The photophysical characteristics of Re-UiO-67 as a function of loading were explored. We analyzed the structural and compositional properties of Re-UiO67 and showed that the photoluminescence properties of rhenium doped MOFs, including emission intensity, maximum, and lifetime, can be tuned by changing the rhenium loading. The photoluminescence of the film made of Re-UiO-67 exposed to different vapors also exhibited vapoluminescence, luminescence vapochromism, and vapotemporism. Understanding of photophysical properties of the Re-doped MOFs material could provide guidance for further photocatalytic, solar energy conversion and sensing applications. In Chapter 4, we developed a covalent fluorine functionalization protocol using hydrofluoric acid at room temperature and reached up to 3.7 wt% of fluorine content on the BNNTs. Using spectroscopic methods and thermal analysis, we verified that fluorine was chemically bonded to boron site. Further nucleophilic BNNTs substitution reactions were performed using alkyl alcohol, providing insights into subsequently tuning surface properties of BNNTs from the fluorinated precursor. In addition, we showed that tuning the hydrophobicity of the surface functional groups leads to dispersibility differentiation in different solvents. This sequential chemical functionalization protocol brings a chance to improve the compatibility of BNNTs towards developing composite materials. | en_US |
| dc.format.mimetype | application/pdf | en_US |
| dc.identifier.citation | Ling, Kexin. "Synthesis, Modifications, and Applications of Porous Nanostructures." (2022) Diss., Rice University. <a href="https://hdl.handle.net/1911/114177">https://hdl.handle.net/1911/114177</a>. | en_US |
| dc.identifier.uri | https://hdl.handle.net/1911/114177 | en_US |
| dc.language.iso | eng | en_US |
| dc.rights | Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder. | en_US |
| dc.subject | porous materials | en_US |
| dc.subject | activated carbon | en_US |
| dc.subject | metal organic frameworks | en_US |
| dc.subject | boron nitride nanotubes | en_US |
| dc.title | Synthesis, Modifications, and Applications of Porous Nanostructures | en_US |
| dc.type | Thesis | en_US |
| dc.type.material | Text | en_US |
| thesis.degree.department | Chemistry | en_US |
| thesis.degree.discipline | Natural Sciences | en_US |
| thesis.degree.grantor | Rice University | en_US |
| thesis.degree.level | Doctoral | en_US |
| thesis.degree.name | Doctor of Philosophy | en_US |
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