Controlling the Electrode Morphology and Surface Energy to Make Ethanol Fuel Cells Based on Pd-Assisted Etched Porous Silicon

The progress in making macro- and mesoporous layers of porous silicon formed through Pd-assisted etching is analyzed. Different formation times and etching solution temperatures (varying from 25 to 75°C) are taken as the parameters. The layers of porous silicon obtained exhibit ethanol electro-oxidation properties. High values of the dissolution rate of the porous silicon are confirmed at a temperature of 75°C resulting in dramatic thinning and decreasing the specific surface area of the macro- and mesoporous layers, respectively. The resulting porous layers have different surface energies and surface areas. The samples exhibit different rates of ethanol dehydrogenation and differ in the number of dehydrogenated ethanol molecules. This is promising to control the activity of the electrode material in ethanol fuel cells.