Formation AgI and ZnI₂ Nanocrystals in AgI-ZnI₂-SiO₂ Hybrid Powders

AgI and ZnI₂ nanocrystals are key components for AgI-ZnI₂-SiO₂ hybrid powders (HPs), which could be potentially important for atmospheric artificial precipitation technology. HPs were created by the “Hydrothermal template cocondensation” method (“HTC” method). Mesoporous silica dioxide (MCM48, MCM41, SBA15, SBA16), silver iodides, and zinc iodides were simultaneously grown under specific conditions. The influence of silica dioxide on AgI and ZnI₂ nanocrystals characteristics (phase, size, and thermal stability) were studied using various physicochemical analysis methods. In addition to crystal features, some structural and textural properties of the AgI-ZnI₂-SiO₂ hybrid as an individual agglomerate and its morphology were determined. This showed that nanocrystal features were dependent on synthesis condition. The influence of the nature of the reagent, which is pH-forming, was manifested at the initial stage of the process, and the morphology of the silica dioxide matrix controlled the crystal properties during the post-synthesis phase. It was established that the thermal stability of AgI and ZnI₂ nanocrystals increased due to the protective shielding function of that SiO₂ matrix.