Synthesis and Characterization of Multistage Porous Sodalite Nanocrystal Aggregate

Using the mixed solution of n-butanol and ethanol as solvent, the sodalite nanocrystal aggregate was prepared by the solvothermal method. The influences of crystallization temperature, molar ratio Na/Al, crystallization time and silane concentration on the morphology, crystallite size, degree of crystallization and pore structure of the as-prepared samples were investigated by X-ray diffraction (XRD), BET, FTIR, Transmission Electron Microscopy (TEM) and scanning electron microscope (SEM). The results reveal that the sodalite nanocrystals are aggregated by self-assembly into the micropore-mesopore-macropore structure. Higher crystallization temperature and longer crystallization time are conducive to the growth of sodalite nanocrystals. It is a necessary condition for the formation of sodalite nanocrystals to keep high molar ratio Na/Al. The higher the molar ratio Na/Al, the more favorable the crystallization of sodalite nanocrystals. The appropriate concentration of silane agent is conducive to the preparation of smaller crystal-sized sodalite nanocrystals. After removing the silane agent by pickling, the sodalite nanocrystal aggregate is a multistage porous structure with the pore volume of 1.0133mL/g and the specific surface area of 449.73m(2)/g.

Automated summary

Using a mixed solution of n-butanol and ethanol as a solvent, a sodalite nanocrystal aggregate was prepared through the solvothermal method. The effects of crystallization temperature, molar ratio Na/Al, crystallization time, and silane concentration on the morphology, crystallite size, degree of crystallization, and pore structure were investigated. The results showed that sodalite nanocrystals self-assembled to form a micropore-mesopore-macropore structure. Higher temperature and longer time favored the growth of sodalite nanocrystals, and a high Na/Al ratio was necessary for their formation. The appropriate silane concentration resulted in smaller crystal-sized sodalite nanocrystals, and removal of the silane agent produced a multistage porous structure with specific properties.