Photoproduction of clean H2 or O2 from water using oxide semiconductors in presence of sacrificial reagent

It is aimed to describe importance of oxide semiconductors with layered or bulk structures for photoproduction of clean H-2 or O-2 from water at room or near room temperature. To achieve this property of semiconductors, either H-2 or O-2 production, sacrificial reagents are employed. First, this short review is started with applications and principle of photocatalysts for water splitting. Followed by soft-chemical synthesis and characterization of layered semiconductor nanocomposites are discussed. Clean production of hydrogen from water using the semiconductor nanocomposites is demonstrated. Then, aqueous combustion synthesis, characterization and clean oxygen production using transition metal-incorporated ZnO are explained. Finally, potential new directions required in this area of research are highlighted. (c) 2006 Elsevier B.V. All rights reserved.