Photocatalytic, morphological and structural properties of the TiO2-SiO2-Ag porous structures based system

Abstract

TiO2-SiO2-based nanocomposites with highly porous structures are gaining ever increasing attention due to their specific properties and large variability of synthesis pathways together with wide information on the impact of the synthesis on the activity of the catalyst. This thereby offers an alternative approach to traditional/commercially available photocatalysts. In our work TiO2-SiO2 based aerogels were obtained and modified with various amount of Ag nanoparticles, using different synthesis pathways. In the first instance their photocatalytic activity was examined in detail, by observing major differences toward salicylic acid and correlating them with their morphological and structural properties (investigating their mesoporous character, band-gap values, crystallinity grade etc.). Applying different techniques such as diffuse reflectance spectroscopy (DRS), X-ray diffraction measurements (XRD), transmission electron microscopy (TEM), Raman- and X-ray photoelectron spectroscopy (XPS) the nanoparticles and their composite morphological and structural details were successfully evaluated. Major differences were observed in the activity towards salicylic acid.