Photocatalytic degradation of acetone in gas-phase: comparison between nano and micro-sized TiO2

Volatile Organic Compounds (VOCs) are widely used in industrial processes and for domestic activities, so generating water and air pollution. Well-known in-door sources of VOCs include cigarette smoke, building materials, paints, lacquers, glues and cleaning products [1]. In particular, the use of paints in industrial processes is responsible for the widespread utilization of organics solvents, such as acetone. Acetone (CH3COCH3) is a common chemical used extensively in a variety of in-dustrial and domestic applications. Therefore, we chose it as a model contaminant. Photocatalytic oxidation of acetone is based on the following overall reaction: CH3COCH3 + 4O2 → 3CO2 + 3H2O The reaction occurs through radical mechanism car-ried out by hydroxyl radicals, with the formation of sev-eral intermediate products such as formaldehyde, formic acid, methanol and acetaldhehyde [2]. The TiO2 photodegradation of organic compounds has been proposed as an alternative Advanced Oxidation Processes (AOP) for the decontamination of air, since the photocatalytic oxidation of organic compounds in gas phase appears to be a promising process for the re-mediation of polluted air. In this paper the photocatalytic efficiency towards acetone degradation of four commercial samples, two micro-sized and two nano-sized TiO2 powders is com-pared. The purpose of this study is to evaluate the feasi-bility of using micro-sized TiO2 instead of nanometric particles, which results in a greater environmental im-pact and higher production costs if compared to the for-mer one