LAUSR

Abstract The inclusion of radiative transfer phenomena during the scale-up of photocatalytic reactions is of utmost importance. Photocatalyst optical transport properties change with any factor affecting agglomeration, such as pH, hydrodynamics, agitation, or reaction extent. Hence, photocatalytic reaction engineering needs fast and straightforward methodologies that allow the in-situ estimation of photocatalyst optical properties. Along this line, the present work presents a specially designed system compatible with any photocatalytic reaction system. The proposed set-up allows the estimation of the extinction coefficient via spectrophotometric procedures. It also enables measurements of laterally scattered radiation, allowing (with a numerical integration procedure) the independent estimation of the single-particle albedo and the phase function considered. The methodology avoids using a nephelometer and an integrating sphere. Instead, it uses a single prototype that allows the fast determination of optical parameters directly in the reaction set-up. The methodology proposed is used to obtain the optical transport properties for Titanium Dioxide under visible light (β*=0.78±0.04 ppm-1m-1, γ=0.92±0.08, g=0.76±0.08) and under UV light (β*=3.90±0.30 ppm-1m-1, γ=0.83±0.03, g=0.89±0.09) and Graphene Oxide under visible light (β*=0.36±0.04 ppm-1m-1, γ=0.135±0.014, g=0.12±0.01).