Large scale production of photocatalytic TiO₂ coating for volatile organic compound (VOC) air remediation

Abstract

In this work, a pure TiO2 colloid was produced at pilot scale of 5 L and deposited on stainless steel with a pilot roll-to-roll line to produce photocatalytic coating for VOC degradation. The pure TiO2 colloid was synthesized with an aqueous sol–gel process, producing crystalline nanoparticles around 4–5 nm (mainly anatase phase) dispersed in water. The crystalline phases were produced at low temperature (<100 ℃) without calcination step. The crystalline coating produced with roll-to-roll process was very thin, around 50 nm. The photoactivity of this coating towards VOC destruction was evaluated on the degradation of acetaldehyde; the measured activity of the coating was 35 ± 5%. With the use of mass spectrometer, it was shown that acetaldehyde was mainly converted in CO2. The durability of the coating was assessed after 1, 2 and 3 weeks, and showed that the photoactivity stayed constant for this period.

Keywords

• aqueous TiO₂
• colloid
• sol–gel process
• pilot scale coating
• photocatalysis
• acetaldehyde degradation