Novel Na0.3WO3/SiO2 solar regulation films for self-cleaning energy-saving window: NIR filtration and superhydrophobicity

In this work, we successfully constructed Na 0.3 WO 3 /SiO 2 superhydrophobic solar regulation films with cooling effect for energy-saving windows. The usage of SiO 2 nanoparticles influenced the wetting performance and cooling property of the composite films . With the increasing use of SiO 2 , the surface of the composite films became rougher and the NIR filtration value became weaker. Due to the hierarchical structures induced by the self-assembly of Na 0.3 WO 3 and SiO 2 nanoparticles, the contact angle of the composite film reached 168.6° and the sliding angle was 4.6° when the amount of SiO 2 nanoparticles was 4 wt%. In addition, the composite film also possessed excellent abrasion resistance and superior self-cleaning performance. Furthermore, the superhydrophobic solar regulation film could filtrate 53.9 % of infrared irradiation. The indoor temperature of the model house can be reduced by 8.4 °C with the help of the Na 0.3 WO 3 /SiO 2 composite films. These excellent performances recommend the Na 0.3 WO 3 /SiO 2 composite films for self-cleaning energy-saving buildings.