The activity of acrylic-silicon/nano-TiO2 films for the visible-light degradation of formaldehyde and NO2

Through a novel green and low-cost emulsion blend method, acrylic-silicon/nano-TiO2 films (ASTF) were prepared showing a broad absorption band in the visible light region and could be used for the photodegradation of indoor gaseous pollutants under visible light irradiation. Compared with acrylic-silicon films, the photodegradation rate of ASTF with TiO2 content of 1% (w/v) increased by almost twice for both gaseous formaldehyde (from 28% to 76.7% at the initial concentration of 0.8 mg/m3) and NO2 (from 20% to 68% at the initial concentration of 3.7 mg/m3) under visible light irradiation for 24 h and 50 h, respectively. The binary gas degradation confirmed the higher affinity of NO2 for ASTF. In addition, ASTF with FeⅢ ion doping (<100 mg/L) showed even higher photocatalytic activity with maximum degradation rate of 83.4% for formaldehyde under visible light irradiation for 24 h. ASTF, as a kind of eco-friendly coating material, could be used easily in domestic buildings for our daily life.