Richard Dvorsky
VÅ B-Technical University of Ostrava, Czech Republic
Title: Preparation and properties of effective photocatalytic nanostructures by application of new patented controlled sublimation
Biography
Biography: Richard Dvorsky
Abstract
For practical sorption and degradation of pollutants and hazardous substances, it is possible to advantageously apply a new hybrid nanomaterials with a high specific surface area and the photocatalytic efficiency. This work presents the preparation of effective photocatalytic core-shell nanostructures C60-TiO2-C60 by application of a new patented method of controlled sublimation. Nanoparticles of commercial photocatalytic material TiO2 (P25 Evonik) were subjected to cavitation ultrasonic deagglomeration in a liquid dispersion medium of solution of fullerene C60 in toluene. Subsequently, in a strong ultrasonic field a new method for preparing of microemulsion nanoparticle core-shell C60-TiO2-C60 was applied. Their aqueous nanodispersion was solidified by very fast freezing, which prevents the crystalline segregation of the dispersion and preserves homogeneous distribution of nanoparticles in the solid amorphous block. By controlled sublimation at the chosen temperature and pressure molecules of water were removed from the frozen dispersion. Controlling of conditions during sublimation provided suitable speed of the phase interface retreat between ice and vacuum and dispersed nanoparticles were organised under these conditions into lamellar nanoaggregates with high specific surface area. Thus prepared nanomaterial showed during degradation tests a high photocatalytic activity.