Surface treatments of metal supports for photocatalysis applications

Abstract One of the most important challenges, for scaling up a photocatalytic system for VOCs abatement to full-scale, is the design of a suitable photocatalyst support. The support has to firmly immobilize the photocatalyst, without using an organic adhesive, and should also withstand relatively high mechanical stresses. Metals may be effectively implemented as a support material, after a corrugation of the surface with electrochemical treatments. In the present work, we treated stainless steel and aluminum supports, evaluating the surface modifications due to the electrochemical treatments, with scanning electron microscopy (SEM) and confocal microscopy. Five samples showing the highest degree of restructuring were selected and spray coated with P25, a TiO 2 photocatalyst, evaluating the mechanical stability of the coating with a standard tape test method. One particular stainless steel sample presented a superior surface restructuring and coating stability. The photocatalytic activity of this sample, evaluated measuring the complete oxidation of acetaldehyde, was tested for 15 h, and compared with sample of TiO 2 -P25 on a ceramic support. The stainless steel exhibited a constant performance after an initial stabilization period. The stainless steel sample showed a slightly higher activity, due to the surface restructuring, increasing the irradiated area available for the coated photocatalyst.