Production of electricity by photoelectrochemical oxidation of ethanol in a PhotoFuelCell

Photocatalytic oxidation of ethanol was carried out in a non-biased photoelectrochemical cell at high pH. The cell was made of two compartments separated by a silica frit, both filled with aerated NaOH electrolyte. The anode electrode bore multilayer nanocrystalline titania, made of either commercial Degussa P25, sol–gel synthesized titania or both. The cathode electrode was made of carbon cloth carrying Carbon Black and Pt as catalyst. When the anode was excited by UVA radiation (363 nm), the cell produced electricity very efficiently. The open-circuit voltage was 0.88 V in the absence and almost 1.2 V in the presence of ethanol. The current increased by more than an order of magnitude by adding ethanol, showing that it is much more efficient to oxidize ethanol than to oxidize (split) water. The performance of the cell improved when a compact titania layer was introduced between the FTO electrode and the thick photocatalytic layer. Ethanol was used as a model fuel but the cell can run on many other organic substances as well. The cell can be used as a source of renewable electricity, by consuming organic wastes under photo-excitation, thus making a PhotoFuelCell.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Ethanol as a model fuel in a Photofuelcell working at high basic pH. ▶ Current multiplication in the presence of ethanol compared to that obtained with water. ▶ High External Quantum Efficiency. ▶ Efficiency increases when commercial nanocrystalline titania is deposited on a compact sol–gel synthesized titania.