Visible Light-Driven Photoelectrochemical Conversion of the By-Products of the Ethanol Fuel Cell into Hydrogen

Because of its low chemical conversion efficiency, the direct ethanol fuel cell forms about 90% of partial oxidation by-products, acetic acid and acetaldehyde. Here, we describe a method allowing one to use these environmentally undesirable species to produce hydrogen. The described visible light-driven photoelectrochemical device employs a mesoporous tungsten trioxide, WO(3), photoanode able to efficiently oxidize CH(3)COOH and CH(3)CHO, and a hydrogen-producing metal cathode. With its bandgap energy of 2.5 eV, the WO(3) film photoanode absorbs blue-green portions of the electromagnetic spectrum up to 500 nm. (C) 2009 The Electrochemical Society. [DOI:10.1149/1.3236383] All rights reserved.