Photocatalytic coating for indoor air purification: Synergetic effect of photocatalyst dosage and silica modification

titanium dioxide (C–TiO2) suspension for the development of a photocatalytic coating for indoor air improvement. The dosage effect of the applied coating and the effect of the ultraviolet pre-treatment, as an activation technique, on the photocatalytic efficiency were studied. A plug-flow experimental setup was employed for the photocatalytic efficiency assessment under realistic indoor air environment. The results showed that the nano-silica addition and the UV pre-treatment enhanced the photocatalytic efficiency of the developed coatings. The nano-silica modification was more beneficial when the coatings were applied in higher photocatalyst dosages (0.84 mg·cm−2 or 1.27 mg·cm−2 of C–TiO2) especially during the UV pre-treatment. The silica-modified samples tested under visible light and reduced flow rate of 1.5 L·min−1 degraded up to 65% and 78% of NO (up to 43% and 60% of NOx) under initial concentration of 0.5 and 0.1 ppm, respectively. Moreover, the reaction rate and reactive uptake coefficient of the developed coatings were compute

Design and performance evaluation of the functional coating for air purification under indoor conditions

The present work aims to develop a photocatalytic coating for the improvement of indoor air quality. Two types of visible-light responsive photocatalysts (powder and suspension form) were applied into a water-based acrylic coating. The applied materials were characterized and the developed coatings were tested for the pollutant removal efficiency under visible-light irradiation. The coatings containing a stabilized C-TiO2 suspension showed nano-scale and uniform particle distributions. UV treatment was found to be necessary, in order to expose the nano-photocatalytic particle and to promote the NOx removal efficiency under visible light irradiation, from 5 hours (5% de-NOx) to 24 hours (23% de-NOx). In addition, the distribution and the incorporation of the catalyst were significantly improved in case of the coatings incorporating C-TiO2 suspension