Reactivity of Silver Iodide (β-AgI) Surfaces A Density Functional Theory Study

International audienceSilver iodide (AgI) aerosols may be produced in severe nuclear accidents and are typically used to favor the formation of droplets, inducing rain. To elucidate their behavior, we study surface stability and reactivity of β-AgI at the density functional theory (PBE + D) level. The most stable surfaces are the (110), (100), and (120). These three surfaces are nonpolar. In contrast, the polar (001) surface is less stable. The water adsorption on these stable surfaces is molecular. The adsorption energy is small (0.30 eV) but increases with the surface coverage because of the formation of hydrogen bonds network between the adsorbed molecules. These surfaces are not very reactive, and the formation of volatile compounds (I2 or IO°) is only possible in presence of strong oxidants such as OH° that may be produced by water radiolysis. © 2018 American Chemical Society