Adsorption of hidrogen peroxide on the surface of silica - titania mixed oxide obtained by the sol-gel processing method

Abstract

This work describes the sol-gel mixed oxide SiO 2 /TiO 2 property, ST, as prepared, and submitted to heat treatment a 773 K, STC. SEM and EDS images show, within magnification used, a uniform distribution of the TiO 2 particles in SiO 2 /TiO 2 matrix. Both, ST and STC adsorb hydrogen peroxide on the surface and through EPR and UV-Vis diffuse reflectance spectra, it was possible to conclude that the species on the surface is the peroxide molecule attached to the Lewis acid site of titanium particle surface, α Ti(H 2 O 2) +. As the material is very porous, presumably the hydrogen peroxide molecule is confined in the matrix pores on the surface, a reason why the adsorbed species presents an exceptional long lived stability.

Arsenic removal from water employing a combined system: photooxidation and adsorption

“…There are some publications that study hydrogen peroxide adsorption onto titanium-based compounds and could explain this behaviour (Muhlebach et al 1970;Boonstra and Mutsaers 1975;Kubota et al 1995;Gonçalves et al 2007). These works report the interaction of hydrogen peroxide in the surface of titanium.…”

“…These works report the interaction of hydrogen peroxide in the surface of titanium. Gonçalves et al (2007) state that Ti (IV) may react with H 2 O 2 forming a yellow-coloured complex according to the reaction…”