Probing TiO₂ as a potential filter material for adsorption and destruction of chemical warfare agents

An atomistic level understanding of mechanisms of adsorption and decomposition of chemical agents on components of filtration materials is required for improvements of existing and design of new materials for chemical protection. Here, we present a comprehensive study of sarin interactions with TiO₂ performed by means of quantum chemical calculations and a combination of IR and XPS measurements. Computational modeling was used to reveal mechanisms of sarin adsorption and decomposition on an ideal (defect free) and hydroxylated TiO₂ rutile (110) and anatase (101) surfaces, whereas experimental measurements were performed for TiO₂ nanoparticles and synthesized mesoporous materials. Calculations revealed strong adsorption of sarin on both the ideal rutile and anatase surfaces, although high activation barriers preclude a decomposition of sarin. The presence of water, on the other hand, reduces binding strength of sarin to rutile and anatase, but promotes the decomposition of sarin. Results of computational modeling were found in good agreement with experimental measurements.