Photocatalytic reduction of metals using polyoxometallates: recovery of metals or synthesis of metal nanoparticles

The ability of polyoxometallates (POM), molecular-anionic metal oxides, to act as photocatalysts in the electron transfer from organic substrates to metal ions will be presented. In the process, illumination at the O -> M charge-transfer band (near-visible and UV regions), renders POM strong oxidants able to abstract electrons from a great variety of organic compounds, including organic pollutants. The photochemically reduced POMs can in turn act as soluble cathodes, able to reduce several metal ions to the elemental state. The process can be implemented for (i) the controlled reductive precipitation and recovery of valuable or toxic metals that can also be combined with the degradation of organic pollutants in a one-pot system and (ii) the synthesis of several metal nanoparticles in a simple and efficient way. To cite this article: A. Troupis et al., C R. Chimie 9 (2006). (C) 2005 Academie des sciences. Published by Elsevier SAS. All rights reserved.