ACCELERATED DECOMPOSITION OF ACTIVE PHOSPHATES ON TIO2 SURFACES

The organophosphate 4-nitrophenyldiethylphosphate (4-NPDEP), a toxic simulant, was deposited on a Nb-doped TiO//2 powder for subsequent photodecomposition. This degradation was observed to occur via hydrolysis by either surface hydroxides or peroxo groups en route to complete mineralization, presumably mediated by the surface mu -peroxo species. Light and O//2 were essential for rapid and complete degradation. A contribution from direct hole and electron oxidation and reduction was also observed.