Core-shell VO2@TiO2 nanorods that combine thermochromic and photocatalytic properties for application as energy-saving smart coatings

Vanadium dioxide (VO 2 ) is a Mott phase transition compound that can be applied as a thermochromic smart material for energy saving and comfort and titanium dioxide (TiO 2 ) is a well-known photocatalyst for self-cleaning coatings. In this paper, we report a VO 2 @TiO 2 core-shell structure, in which the VO 2 nanorod core exhibits a remarkable modulation ability for solar infrared light and the TiO 2 anatase shell exhibits significant photocatalytic degradation of organic dye. In addition, the TiO 2 overcoating not only increased the luminous transmittance of VO 2 based on an antireflection effect, but also modified the intrinsic colour of VO 2 films from yellow to light blue. The TiO 2 also enhanced the chemical stability of VO 2 against oxidation. This is the first report of such a single nanoparticle structure with both thermochromic and photocatalytic properties that offer significant potential for creating a multifunctional smart coating.