Visible-light photocatalytic activity of gold nanoparticles supported on template-synthesized mesoporous titania for the decontamination of the chemical warfare agent Soman

Mesoporous titania containing gold nanoparticles has been found to be an efficient photocatalyst for the visible-light decontamination of Soman. This contrasts with the complete lack of visible-light activity of analogous mesoporous titania sample without containing Au and is attributed to light absorption by the gold nanoparticles surface plasmon band. The possibility that Soman degradation occurs by light-induced heating is unlikely since no variation of the temperature is observed in the irradiation. The solid photocatalysts have been prepared in a single step in which incorporation of gold and formation of titania occur in the same sol-gel process. It was observed that the molar proportion of Pluronic added to the synthesis sol as template to produce mesoporosity in the material plays an important role controlling the textural properties, surface area and pore diameter, intensity of the surface plasmon band and gold loading of the solid photocatalysts. The visible-light photocatalytic activity of mesoporous titania containing gold nanoparticles towards deadly Soman is remarkable and it constitutes an environmentally friendly system operating under ambient light at the green atmosphere without the need of corrosive or toxic chemicals. (C) 2010 Elsevier B.V. All rights reserved.