Date of Award
9-4-2015
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Tito Viswanathan
Abstract
Doped carbon materials have gained a lot of attention recently due to their wide array of applications, for example, in dye degradation, energy conversion and storage, electrocatalysis, sensors and electronics. These doped carbon materials are claimed to have a tremendous potential to substitute expensive metal based electrocatalysts in fuel cell and supercapacitor applications. A recently established microwave assisted technique, which does not make use of any inert or reducing gas during the synthesis, was utilized to synthesize doped carbon materials. The method is simple, rapid, economical and high yielding. Renewable resource materials like tannin, spent coffee grounds and thiamine were utilized as the predominant carbon source along with dopant sources like silicone fluid, polyphosphoric acid and ammonium polyphosphate to synthesize Si, P co-doped C (SiPDC), P, N co-doped C (PNDC) and Si, P, N doped carbon (SiPNDC) materials. Varying proportions of precursor materials were utilized to develop different doped carbon materials. Scanning electron microscopy revealed that the synthesized doped carbon materials have different morphologies. X-ray photoelectron spectroscopy confirmed the presence of dopants (Si, N, P and O) in the doped carbons. The materials have surface areas up to ̴1000 m2 g-1 with presence of micropores, mesopores and macropores. The synthesized doped carbon materials showed promise in O2 reduction reaction (ORR) for fuel cells under alkaline conditions. All the synthesized materials exhibited potential to reduce O2 by a 4 e- mediated process as evidenced from rotating disk electrode studies as well as rotating ring disk electrode studies. The doped carbon materials also exhibited electrochemical stability over 2000 cycles in 0.1 M KOH. These materials were also investigated as electrode materials for supercapacitor applications in both acidic and alkaline environments. The materials exhibited promise by generation of a specific capacitance value as high as 318 F g-1 in 6M KOH. The doped carbon materials were also discovered to be electrochemically stable for supercapacitor applications over 2000 cycles in 6M KOH.
Recommended Citation
Ramasahayam, Sunil Kumar, "Novel Selected Hetero-Atom Doped Carbon from Renewable Resource Materials for Fuel Cell and Supercapacitor Applications" (2015). Theses and Dissertations. 624.
https://research.ualr.edu/etd/624
