Decomposition of organophosphorus compounds on photoactivated TiO2 surfaces

摘要: Aqueous solutions of the organophosphorus compounds 4-nitrophenyl diethylphosphate (Paraoxon or 4-NPDEP), diethyl-p-nitrophenyl thiophosphate (Parathion 4-NPDETP), O,O-dimethyl-S-(1,2-dicarbethoxyethyl)-phosphorodithioate (Malathion DM-S-DCPT), 4-nitrophenylethylphenyl phosphinate (4-NPEPP) and 4-nitrophenylisopropylphenyl (4-NPIPP) are totally decomposed into CO2 corresponding mineral acids by irradiation in a solar simulator presence dispersed particles n-type semiconductor, TiO2 (anatase, B.G. = 3.23 eV). Addition strongly oxidizing species such as K2S2O8, H2O2, NaIO4 KBrO3 to these enhances dramatically rate catalytic activity inhibition electron hole back-reaction well direct oxidation substrate strong oxidants themselves. A mechanism degradative on involving epoxidation surface peroxo is proposed.