High surface area gold electrodes are very good substrates for biosensors, catalysis and drug delivery. Their performance is characterized by good sensitivity, low detection limit and high signal. As a result, extensive research is being carried out in this field using different approaches of fabrication to generate high surface area porous electrodes of different morphology, pore size and structure. The morphology of the electrodes can be changed based on whether the approach involves a template or not, types of metal deposition, method and time of dealloying etc. The deposition of metal can be carried out using various approaches such as electroless deposition, electrochemical deposition, combination of electroless and electrochemical deposition, pulsed laser deposition, laser deposition etc. These electrodes can then be used in electrochemical measurements and their performance compared with an unmodified flat gold electrode. We used a template based approach, combined with electrochemical deposition, to fabricate macroporous, macro-nanoporous and nanoporous gold electrodes. To generate nanopores, in case of macro-nanoporous and nanoporous gold electrodes, we used gold-silver alloy electrochemical deposition method, followed by chemical dealloying. The morphology of electrodes was later observed under HITACHI Scanning Electron Microscope (SEM) and their elemental composition studied using HITACHI Energy Dispersion Spectroscopy (EDS). The electrodes were used in electrochemical measurements and their voltammetric data was compared. These measurements involved the determination of surface area, faradaic current using redox molecules with fast and slow electron transfer and charging current in KCl. Surface adsorption of dopamine was studied and detection of dopamine in the presence of ascorbic acid was carried out.

Ceria is a very important catalytic material for fuel reforming in SOFCs and CO poisoning in PEM fuel cells. Especially, the design of a new generation SOFC requires the in-situ reforming of hydrocarbon fuels. In this work, nanostructured ceria was developed via a controlled hydrothermal process in a mixed water-ethanol medium. The microstructure, formation mechanism, and their surface catalytic properties were investigated.

"Despite advancement in the field, energy storage technology has plateaued in recent years. With Li-ion batteries likely reaching the peak of their capability, researchers are developing new technologies such as supercapacitors and other hybrid energy storage devices. Current electrodes for supercapacitors consist primarily of carbon material, such as activated carbon, graphite, graphene, and functionalized multi-walled carbon nanotubes (f-MWCNT). f-MWCNTs are a promising nanomaterial due to their high power density, low cost, low toxicity, high stability, good electrical conductivity, and high active specific surface area (area per mass). The major disadvantage of MWCNT supercapacitors is their lower energy density relative to commercial batteries. However, the addition of metal oxides such as MnO and CoO to f-MWCNT electrodes, can provide a cost-effective energy density boost to supercapacitors through pseudocapacitive effects, while still maintaining the attractive properties of pure f-MWCNT electrodes. This thesis investigates charge storage/delivery properties of Mn/Co-oxides with the aim of using them to functionalize f-MWCNTs and increase the electrode material capacitance.It was found that by functionalizing f-MWCNT with Mn/Co-oxides, a significant increase in specific capacitance was achieved. In galvanostatic charge/discharge (GCD) tests run at 0.2 mA/cm2 the f-MWCNT yielded 288±10F/g, while the Mn0.5/Co0.5-oxide/f-MWCNT electrode yielded 430±14 F/g. Cyclic voltammetry (CV) tests yielded even higher values at low scan rate, 752±85 F/g. It was also found that pure Mn0.5/Co0.5-oxide behaves more as a battery electrode material than as a supercapacitor electrode material, yielding apparent capacitance of 4497±57 mF/cm2 (1.38mAh/cm2). The high apparent capacitance (e.g. energy storage and delivery) was due to intercalation of cations (Na+ or Li+) into the crystalline structure of the Mn0.5/Co0.5-oxide phase in order to compensate the redox transition change. However, the Mn0.5/Co0.5-oxide/f-MWCNT electrodes were not found to enable cation intercalation, and the resulting capacitance was lower (752±85 F/g). All samples showed high stability and highly porous microstructure. Metal oxides were found to consist of MnO, MnO2, CoO, Co3O4 and metal hydroxides." --