Optical properties of silica-supported TiO2 photocatalysts aqueous suspensions: consequences for photoreactor design

MARUGAN, J.; VAN GRIEKEN, R.; ALFANO, O.M.; CASSANO, A.E.

Gottingen, Alemania

Conferencia; The Second European Conference on Oxidation and Reduction Technologies for Ex-Situ and In-Situ Treatment of Water, Air and Soil; 2005

Redox Technologies

Despite the large number of supported TiO2 photocatalysts reported in the last years, only a few attempts have been made to determine the optical parameters, absorption and scattering coefficients, of the aqueous suspensions of this kind of materials. These values are required for the evaluation of the radiation absorbed by the catalyst suspension to quantify the absolute quantum yields of the photocatalytic reaction. The optical properties are also needed for the rigorous design and scaling-up of the photocatalytic reactors through the solution of the Radiative Transfer Equation (RTE) [1]. This work deals with the evaluation of the absorption and scattering coefficients of several silica-supported TiO2 photocatalysts recently developed [2]. Experimental and theoretical modifications from a previously reported procedure [3] have been required to quantify the optical properties of these materials. The influence of the titanium dioxide loading and the type of silica support is studied. Differences with the optical properties of unsupported TiO2 and their consequences for the photoreactor design are also analyzed.