TiO₂ Macroscopic Fibers with Enhanced Photocatalytic Properties Obtained through a Scale‐Up Semi‐Industrial Process

Abstract

We describe the generation and properties of TiO 2 -based macroscopic fibers designed for the photodecomposition of volatile organic compounds (VOC). We made use of a continuous industrially scalable extrusion process employing hybrid sols of amorphous titania nanoparticles, polyvinyl alcohol (PVA), and optionally latex nanoparticles. This process allowed for the continuous generation of hybrid TiO 2 /latex/PVA or TiO 2 /PVA macroscopic fibers. Upon thermal treatment in air, we obtained biphasic porous fibers containing the anatase phase of TiO 2 with 10-15% of brookite. These fibers, which can be manufactured as several hundred meters of length reels, provide significantly improved phototocatalytic efficiency compared to our previous work. Their efficiency is now comparable to the commercial Quartzel 1 PCO photocatalyst for gas-phase acetone mineralization.

Competition and Coexistence of Raman and Random Lasing in Silica‐/Titania‐Based Solid Foams

“…We would like to underline that the synthetic route employed here makes use of strong acidic conditions where oxonium ions avoid fast condensation of titania, without the need either of chelatant or titania–silica single source precursor . We have previously employed this route to generate either pure titania foams, playing with either concentrated emulsions or air–liquid foams as templating agents or fibers generated through an extrusion process . In all cases, the strong acidic conditions allowed to shape the materials at ease at the sol–gel state while adding ammonia to promote oxonium deprotonation, thereby increasing the titania network polycondensation kinetic.…”