Complexing Carbon Nanomaterials and Reactive Metal Species for Selective Chemical Sensing and Tunable Catalysis
This thesis highlights strategies for functionalizing carbon nanomaterials with reactive metal species for applications in chemical sensing and electrocatalysis. In Chapter 1, we begin with an introduction of chemiresistive sensing using functionalized carbon nanotubes (CNTs). This introduction summ...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Published: |
Massachusetts Institute of Technology
2023
|
| Online Access: | https://hdl.handle.net/1721.1/152123 https://orcid.org/0000-0001-5308-4576 |
| Summary: | This thesis highlights strategies for functionalizing carbon nanomaterials with reactive metal species for applications in chemical sensing and electrocatalysis. In Chapter 1, we begin with an introduction of chemiresistive sensing using functionalized carbon nanotubes (CNTs). This introduction summarizes the design, fabrication, characterization, and evaluation of carbon nanotube-based chemiresistive sensors. Potential strategies for optimizing sensitivity and selectivity are also discussed. Typical applications of CNT-based chemiresistive sensing are also surveyed. In Chapter 2, we report the synthesis of Pentiptycene Polymer/Single-Walled Carbon Nanotube Complexes and their applications in the selective detection of benzene, toluene, and o-xylene using chemiresistive and quartz crystal microbalance-based methods. In Chapter 3, we report a method to effectively immobilize transition metal selectors in close proximity to the SWCNT surface using pentiptycene polymers containing metal-chelating backbone structures. We have identified sensitive, selective, and robust copper-based chemiresistive ammonia sensors displaying low parts per billion detection limits. We have added these hybrid materials into the resonant radio frequency circuits of commercial near-field communication (NFC) tags to achieve wireless detection of ammonia at physiologically relevant levels, offering a non-invasive and cost-effective approach for early detection and monitoring of chronic kidney diseases. In Chapter 4, we report that iptycene-containing poly(arylene ether)s (PAEs) show to limit the palladium nanoparticles (Pd NPs) growth and stabilize the Pd NPs dispersion. SWCNT-based chemiresistors and graphene field-effect transistors (GFETs) using these PAE-supported small Pd NPs are sensitive, selective, and robust sensory materials for hydrogen gas under ambient conditions. In Chapter 5, we describe chemiresistors based on SWCNTs containing small and highly reactive copper-based nanoparticles in sulfonated pentiptycene poly(arylene ether)s (PAEs). The sensors show exceptional sensitivity to trace hydrogen sulfide in wet air with a low-ppb detection limit, high selectivity over a wide range of interferants, and month-long stability under ambient conditions. In Chapter 6, we report a SWCNT-based chemiresistor catalyst combination that can detect ppb levels of ethylene in air, driven by the chemoselectivity of the catalytic transformation. The utility of this ethylene sensor is demonstrated in the monitoring of senescence in red carnations and purple lisianthus flowers. In Chapter 7, we report SWCNT-based chemiresistive sensors based on a catalytic system comprising a copper complex and TEMPO cocatalyst, enabling the sensitive, selective, and robust detection of trace ethanol in air. In Chapter 8, we report the synthesis of carbon-nanomaterial-based metal chelates that enable effective electronic coupling to electrocatalytic transition metals. The defined ligands on the graphene surfaces enable the formation of structurally precise heterogeneous molecular catalysts. We demonstrate that the densely functionalized metal-chelated carbon nanomaterials are effective heterogeneous catalysts in the oxygen evolution reaction with low overpotentials and tunable catalytic activity. |
|---|