ECOSHOPPING EU PROJECT - PHOTOCATALYTIC ACTIVITY OF COMMERCIAL INDOOR PAINTS VERSUS NEW DOPED TiO2-BASED COMPOUNDS: INFLUENCE OF EXPERIMENTAL CONDITIONS AND LIGHTING SYSTEMS

EcoShopping project (Energy efficient & Cost competitive retrofitting solutions for Shopping buildings) aims to build a holistic retrofitting solution for commercial buildings to reduce primary energy consumption down to less than 80kWh/m2 per year and increase the share of RES (Renewable Energy Sources) more than 50% compared to the state of the art [1]. The approach is systemic by developing the most suitable solution for different applications. As some examples: novel thermal insulation solutions; easy to install and cascadable daylighting technologies; heating, ventilation and air conditioning retrofitting systemic approach based on RES; integrated solution way based on the intelligent automation unit concept. Indoor air quality, moreover, represents one of the most crucial aspects for a high level wellness and it needs to be strictly controlled. Photocatalytic - self-cleaning paints represent a considerable smart and economical solution for indoor pollutants removal. The self-cleaning action, indeed, involves the mineralization of organic compounds, thus obtaining carbon dioxide and water as final products. The oxidation process of self-cleanings paints, of course, is also applicable to biological contamination, such as moulds, by degradation of cellular membrane [2-4]. Three photocatalytic indoor commercial paints were selected taking into account the technical sheets provided by the producers, with special consideration with respect to the required lighting system for the photocatalytic action execution. Commercial paints were fully characterized in order to obtain a composition-photoactivity correlation. The new developed TiO2-based photocatalysts were prepared for obtaining an improved photoactivity and a more extended exploitation of the visible light. The commercial paints were then compared to new-developed TiO2 based photocatalysts and tested under different experimental conditions (pH and organic pollutant probes) and different lighting systems (UVA, UVC, Xenon, fluorescent and LED lamps) in order to evaluate the actual photocatalytic properties. Degussa P25 was always employed as standard reference for comparison. The results show that the new compounds offer an improved activity with respect to P25 and with respect to the commercial paints in acidic condition. It was also proved that the photocatalytic activity depends on the target molecule and, as a consequence, on the experimental conditions.