Photocatalytic oxidation of an organophosphorus simulant of chemical warfare agent by modified TiO2 nanophotocatalysts

TiO2 nanoparticles, as a photocatalyst for oxidation of dimethyl methylphosphonate (DMMP) as an organophosphorus simulant of chemical warfare agent, were prepared by using sol-gel method. The prepared nanoparticles were then modified with transition metals in order to decrease the electron-hole recombination and increase the photocatalytic activity. Transition metal ions including Pt, Pd and Ni were used for this purpose. The prepared samples were characterized by different analysis methods, and Photocatalytic mechanism was studied over the unmodified and modified photocatalysts. The effect of some operational parameters such as catalyst dosage, initial DMMP concentration and type and amount of loading the transition metal on the photocatalytic activity was investigated. The results showed that the best photooxidation of DMMP was obtained with 1% Pd/TiO2. The optimum conditions for catalyst dosage and initial DMMP concentration were 20 g L^-1 Pd and 0.138 M, respectively.