Studying adsorption and detoxification of sulfur mustard chemical warfare onto ZnO nanostructures

Abstract

Sulfur mustard is a strong vesicant, leading to severe skin damages as well as eye blistering and may lead to death if inhaled. Unfortunately, there are no effective treatments for mustard-induced injury. Hence, there is considerable attention in the development of materials that can absorb or detoxify mustard gas. In the first part of this report, detoxification of sulfur mustard is performed on the synthetic ZnO nanosheets. The intended ZnO nanostructure is prepared via a simple and efficient method and characterized by means of FT-IR, XRD, FESEM, and XPS to confirm formation of the desired nanosheets. Then, detoxification and degradation of sulfur mustard is carried out on the prepared ZnO nanostructures at room temperature and a good rate for sulfur mustard detoxification was attained at the initial stages of the reaction (1−12 h) with a rate constant of 0.081 h−1 and a half-life of 8.4 h. At the second part of the present study, the density functional calculations including B3LYP and wB97XD are used to monitor the adsorption of this toxic material on the surface of various ZnO nanoclusters (ZnONCs). The values of adsorption energy of mustard gas are determined in the range of about −16 to −54 kcal/mol with enthalpies in the range of about −15 to-51 kcal/mol and the Gibbs free energies in the range of −3 to −28 kcal/mol at 298 K based on B3LYP level of theory. The geometry parameters are calculated for all geometries by consideration of the charge analysis and frontier molecular orbitals. Findings revealed that these systems are useful chemical sensors for sulfur mustard. Moreover, it is found that the CCL-ZnONS can effectively interact with this material and modifies the sensitivity of zinc oxide towards this agent.