The effects of Ti/Si molar ratio and of the mesoporous silica structure were investigated measuring adsorption capacity and photocatalytic degradation of toluene in selfconstructed gas reactor system. The adsorption capacity was decreasing as a function of the increasing Ti/Si molar ratio. However, the photocatalytic degradation proceeded faster for the Ti/Si molar ratio 1/1 compared to ratios 1/2 and 2/1. In general, the photocatalytic activity was considerably improved by using supported titania–silica catalyst with regard to an unsupported titania powder prepared from the same titania sol.
COBISS.SI-ID: 1544955
Surfactant-assisted anatase mesoporous TiO2 transparent films, along with P25 translucent films were successfully synthesized and deposited by dip-coating technique. Prepared films were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and N2 adsorption-desorption measurements. The hydrophilicity of films was assessed by water contact angle technique. The results revealed that the surfactant-assisted sol-gel films were homogeneous, crack-free, contained anatase phase only with small grain size, and showed an increase in BET surface area and wide range of pore size distribution compared to non-surfactant treated sample. The optical properties and photocatalytic activity of the films for an azo dye, Plasmocorinth B (PB) degradation were analyzed with UV-Vis spectrometer. The photocatalytic activity of the synthesized anatase TiO2 films having high optical quality is comparable to the activity of reference commercial powder P25 films. Relevant results are presented and discussed as a function of the structure and morphology of coatings, which control enables a direct tailoring of the functional response.The high porosity, uniformity, transparency, reliability, photocatalytic activity, good adhesion with the substrate and the excellent performance under cycling operation displayed by surfactant-assisted anatase TiO2 coatings make it a good candidate to be considered in new emerging engineering applications.
COBISS.SI-ID: 1829479
The aim of this study was to prepare highly active immobilized titania/silica photocatalyst and to test its performance in situ toward degradation of toluene as one of the major toxic indoor contaminants. The results show that nontransparent highly photocatalytically active coatings based on the silica/titania binder and homogeneously dispersed TiO2 powders were obtained on the Al sheets.The crystalline structure of titania was not altered upon addition of the binder, which also prevented inhomogeneous agglomeration of particles on the photocatalyst surface. The photoactivity results indicate that the adsorption properties and photocatalytic activity of immobilized photocatalysts with the silica/titania binder and underlying protective layer were very effective and additionally, they exhibited a considerably improved adhesion and uniformity.
COBISS.SI-ID: 2561531
The chapter considers recent achievements in the functionalization of porous silicates by manganese and TiO2. Case studies of promising manganese functionalized porous silicate as catalysts for water purification, and TiO2 functionalized porous silicate as catalysts for air purification are presented.
COBISS.SI-ID: 5339418
For air-cleaning, TiO2 photocatalysis represents one of the very efficient advanced oxidation processes (AOPs) that can decompose chemically and microbiologically stable volatile organic compounds (VOCs). However, the photocatalytic activity of nanocrystalline TiO2 powders can be significantly suppressed due to TiO2’s poor adsorption characteristics for organic compounds and its relatively low surface area. The present study sought to solve this problem by immobilising nanocrystalline TiO2 in the porous silicate substrate. Two titania sources were used in an aqueous solution form: a suspension from a TiO2 producer in Slovenia, Cinkarna Celje (CC 40) and a TiO2 sol, prepared by a low-temperature synthesis developed at the University of Nova Gorica (TiO2- UNG). Two different types of mesoporous silica were used: SBA-15 with an ordered hexagonal pore arrangement and KIL-2 with disordered inter-particle mesoporosity. The structural characteristics, adsorption properties and photocatalytic activity of catalysts deposited on aluminium plates as thin films were investigated. CC-40 exhibited higher adsorption and photocatalytic activity than TiO2- UNG due to the greater quantity of Ti-OH groups on its surface. The addition of mesoporous silica led to higher adsorption and catalytic activity for both TiO2 sources. SBA-15 was more efficient than KIL-2.
COBISS.SI-ID: 5437466