Specific properties on TiO2 photocatalysis to decompose isopropyl methylphosphonofluoridate and dimethyl methylphosphonate in Gas Phase

Abstract The specific differences on TiO 2 photocatalytic decomposition rates of vaporized isopropyl methylphosphonofluoridate, sarin (GB), r GB as a real Chemical Warfare Agent (CWA) and vaporized dimethyl methylphosphonate (DMMP), r DMMP as CWA simulant in gas phase have been investigated by Gas chromatography/mass spectrometry (GC/MS) analysis in ambient. The concentration of GB molecules adsorbed at the surface of TiO 2 in the dark, C GB , was 28 times larger than C DMMP in the dark. The r GB was then 3.3 times faster than the r DMMP . The results were explained by taking into account faster hydrolysis of GB molecules at the surface of TiO 2 and the larger diffusion constant of GB in the gas phase than DMMP molecules. The effect of F − adsorption at the surface of TiO 2 as fluoridated surface on the TiO 2 photocatalysis was also studied.