Visible light-driven photoelectrochemical conversion of the by-products of the ethanol fuel cell into hydrogen

Abstract

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, WO3, photoanode able to efficiently oxidize CH3COOH and CH3CHO, and a hydrogen-producing metal cathode. With its bandgap energy of 2.5 eV, the WO3 film photoanode absorbs blue-green portions of the electromagnetic spectrum up to 500 nm. © 2009 The Electrochemical Society.