Preparation and photo catalytic application of different TiO_2 and Zn(OH)_2/ZnO nanoparticles and hydrophelic/hydrophobic layered silicates

摘要

TiO_2 nanosol particles were prepared by acidic hydrolysis of titanium tetraisopropoxide, and tlie incoiporation of tlie anatase nanoparticles was next carried out between tlie layer silicate sheets by heterocoagulation method. TiO_2/montmorillonite nanocomposites with high specific surface areas (a~S_(BET_ = 130-284 m~2 g~(-1)) were characterized and tested as photocatalysts by mineralization of phenol. Self-assembled multilayer films from Zn(OH)_2/ZnO nanoparticles and hectorite were prepared and tlie optical and structural properties were investigated. Significant photodegradation of p-naphtol and kerosene was found in tlie presence of tlie nanofilms, in tlie flow photocatalytic experiments. The degradation of 2-chlorophenol was investigated by a combination of TiO_2-based photocatalysis and adsorption. The differently prepared adsorbent-photocatalyst systems were characterized by X-ray diffraction measurements. The most advantageous situation was found when die hexadecylpyridinium chloride-treated montmorillonite was used as adsorbent and Degussa P25 TiO_2 as photocatalyst, for which tlie liighest rate of oxidation of 2-chlorophenol was observed. In this case tlie photocatalytically recovered adsorbent may be re-used without further regeneration.