New intelligent multifunctional SiO(2)/VO(2) composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity

Highly transparent, energy-saving, and superhydrophobic nanostructured SiO(2)/VO(2) composite films have been fabricated using a sol–gel method. These composite films are composed of an underlying infrared (IR)-regulating VO(2) layer and a top protective layer that consists of SiO(2) nanoparticles. Experimental results showed that the composite structure could enhance the IR light regulation performance, solar modulation capability, and hydrophobicity of the pristine VO(2) layer. The transmittance of the composite films in visible region (T (lum)) was higher than 60%, which was sufficient to meet the requirements of glass lighting. Compared with pristine VO(2) films and tungsten-doped VO(2) film, the near IR control capability of the composite films was enhanced by 13.9% and 22.1%, respectively, whereas their solar modulation capability was enhanced by 10.9% and 22.9%, respectively. The water contact angles of the SiO(2)/VO(2) composite films were over 150°, indicating superhydrophobicity. The transparent superhydrophobic surface exhibited a high stability toward illumination as all the films retained their initial superhydrophobicity even after exposure to 365 nm light with an intensity of 160 mW(.)cm(−2) for 10 h. In addition, the films possessed anti-oxidation and anti-acid properties. These characteristics are highly advantageous for intelligent windows or solar cell applications, given that they can provide surfaces with anti-fogging, rainproofing, and self-cleaning effects. Our technique offers a simple and low-cost solution to the development of stable and visible light transparent superhydrophobic surfaces for industrial applications.