Non-photochemical catalytic hydrolysis of methyl parathion using core-shell Ag@TiO 2 nanoparticles.

Highly water-dispersible core-shell Ag@TiO 2 nanoparticles were prepared and shown to be catalytically active for the rapid degradation of the organothiophosphate pesticide methyl parathion (MeP). Formation of the hydrolysis product, p -nitrophenolate was monitored at pH 7.5 and 8.0, using UV-Vis spectroscopy. 31 P NMR spectroscopy confirmed that hydrolysis is the predominant pathway for substrate breakdown under non-photocatalytic conditions. We have demonstrated that the unique combination of TiO 2 with silver nanoparticles is required for catalytic hydrolysis with good recyclability. This work represents the first example of MeP degradation using TiO 2 doped with AgNPs under mild and ambient conditions. Analysis of catalytic data and a proposed dark mechanism for MeP hydrolysis using core-shell Ag@TiO 2 nanoparticles are described.