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Full-Text Articles in Physical Sciences and Mathematics
Modification Of Chemical Vapor-Deposited Carbon Electrodes With Electrocatalytic Metal Nanoparticles Through A Soft Nitriding Technique, Enoch Amoah
Electronic Theses and Dissertations
Metal nanoparticles have been widely used for many catalytic and electrocatalytic applications due to their larger surface area-to-volume ratios and higher densities of active sites compared to bulk materials. This has resulted in much interest in understanding the electrocatalytic behavior of metal nanoparticles with respect to their structure. However, most research on this topic has employed collections of nanoparticles. Due to difficulties in controlling and characterizing particle loading and interparticle distance in nanoparticle ensembles, single nanoparticles studies have recently become a topic of great interest. In this study, a soft nitriding technique was applied to chemical vapor-deposited carbon ultramicroelectrodes (UMEs) …
Comparing Laser Assisted Pulling And Chemical Vapor Deposition Methods In The Fabrication Of Carbon Ultramicro- And Nanoelectrodes, Theophilus Neequaye
Comparing Laser Assisted Pulling And Chemical Vapor Deposition Methods In The Fabrication Of Carbon Ultramicro- And Nanoelectrodes, Theophilus Neequaye
Electronic Theses and Dissertations
Ultramicroelectrodes (UMEs) (limiting dimensions <~25 μm) and nanoelectrodes (<~100 nm) exhibit enhanced electrochemical properties compared to macroscopic electrodes. Their small sizes and enhanced properties make them well-suited for various interesting and important applications such as measuring redox-active species in nonaqueous solvents, studying intermediates of fast electrochemical reactions, and investigating electrochemical and electrocatalytic properties of single nanoparticles. While UMEs are commercially available, nanoelectrode fabrication is still largely confined to research labs. Various methods for constructing nanoelectrodes have been reported and continue to be developed, but most require considerable expertise, and comparisons between different fabrication processes are lacking. In this work, a comparison of laser-assisted pulling and chemical vapor deposition (CVD) methods of electrode fabrication is made with the aim of optimizing production of carbon nanoelectrodes for single nanoparticle electrochemical measurements. By examining effects of pulling parameters, post-pulling treatments, and CVD processing, electrodes as small as ~50 nm were successfully produced.
Immobilization Of Gold Nanoparticles On Nitrided Carbon Fiber Ultramicroelectrodes By Direct Reduction, George Affadu-Danful
Immobilization Of Gold Nanoparticles On Nitrided Carbon Fiber Ultramicroelectrodes By Direct Reduction, George Affadu-Danful
Electronic Theses and Dissertations
Due to enhanced properties such as large surface area-to-volume ratio, metal nanoparticles are often employed as catalysts for various applications. However, most studies involving nanoparticle catalysts have been conducted on collections of particles rather than single nanoparticles. Results obtained for ensemble systems can be difficult to interpret due to variations in particle loading and interparticle distance, which are often challenging to control and characterize. In this study, two immobilization strategies for incorporating gold nanoparticles (AuNPs) on carbon fiber ultramicroelectrodes (UMEs) were compared with the goal of extending these techniques to nanoelectrodes for studies of single AuNPs. Both layer-by-layer deposition of …