Abstract
In pursuit of effective and less toxic materials for energy conversion, this study explored various materials for potential application in alkaline direct alcohol fuel cells (ADAFC) and perovskite solar cells (PSC). Alcohol electrooxidation on selected palladium-based electrocatalysts was investigated in alkaline media using various electrochemical techniques. For the first time, carbon nanodots (CNDs) were synthesised by pulverising multi-walled carbon nanotubes (MWCNTs) and functionalised using aqueous sodium hydroxide. Palladium-based nanocatalysts supported on functionalised carbon nanodots (fCNDs) blended with metal oxides promoters were prepared by sonochemical-assisted borohydride reduction method. Zirconium dioxide (ZrO2) and tungsten (VI) oxide (WO3) were selected as promoters while nickel (Ni) and cobalt (Co) were used as cocatalysts to prepare four electrocatalysts denoted by Pd/fCNDs-ZrO2, Pd/fCNDs-WO3, PdNi/fCNDs-WO3 and PdCo/fCNDs-WO3. The ratio of metal oxide to fCNDs was fixed at 1:4 to maintain good electrical conductivity of the support material. Physicochemical properties of the synthesised materials were studied by various microscopic and spectroscopic techniques such as transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD) and X-ray photoelectron spectroscopy (XPS). Alcohol fuel oxidation on the prepared electrocatalysts was investigated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) techniques in KOH electrolyte. Synthesised Pd/fCNDs (8.23 wt. % Pd) and commercial Pd/C (10 wt. % Pd) electrocatalysts were used as benchmark standards...
Ph.D. (Chemistry)