Visible light-activated photocatalytic activity of TiO2–crystal violet based superhydrophobic paint against VOCs in indoor air†

Abstract

With industrial growth, air pollution has also increased. Air pollution is accountable for several diseases and numerous deaths. Volatile organic compounds (VOCs) are one of the most common classes of air pollutants and are mostly caused by anthropogenic activities. These VOCs have adverse effects on human health as well as on the environment. Photocatalytic oxidation is one of the most common methods available to get rid of VOCs. Photocatalytic oxidation (PCO) is usually performed under UV light, but various photocatalysts, which can work under the visible region of light (white light), have also been reported lately. Recently, PFOTES–CV-based visible light activated-superhydrophobic TiO2 paints have been reported to have bactericidal activity according to the literature. In this study, we have used these TiO2-based paints to study their photocatalytic efficiency against VOCs. The effects of multiple parameters including the input concentration of VOCs (2–5 ppm), amount of PFOTES (1–5%), light power source (8, 24 W), and humidity (60–70%) have been studied. Substantial photocatalytic efficiency was observed against toluene, p-xylene, and acetaldehyde. ∼92% against toluene, ∼99% against p-xylene, and considerable removal efficiency against acetaldehyde were found with the paint made with 3% PFOTES. Characterization of the photocatalysts was carried out by XPS, FTIR, and DRS. The PCO reactor under visible light was used for the photocatalytic decomposition reaction and the gas analysis was performed by GC/MS.