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

Abstract

Vanadium dioxide (VO2) is a Mott phase transition compound that can be applied as a thermochromic smart material for energy saving and comfort, and titanium dioxide (TiO2) is a well-known photocatalyst for self-cleaning coatings. In this paper, we report a VO2@TiO2 core-shell structure, in which the VO2 nanorod core exhibits a remarkable modulation ability for solar infrared light, and the TiO2 anatase shell exhibits significant photocatalytic degradation of organic dye. In addition, the TiO2 overcoating not only increased the luminous transmittance of VO2 based on an antireflection effect, but also modified the intrinsic colour of VO2 films from yellow to light blue. The TiO2 also enhanced the chemical stability of VO2 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.

Superior electrochemical properties of rutile VO2-carbon composite microspheres as a promising anode material for lithium ion batteries

“…The most stable structure of vanadium dioxide is the tetragonal rutile structured VO 2 (R), which is stable from 68 C to 1540 C [22]. Monoclinic VO 2 (M) phase transforms into tetragonal rutile VO 2 (R) at about 68 C [22][23][24][25]. The electrochemical properties of metastable VO 2 (B) with various morphologies, such as nanorods, nanowires, nanoribbons, nanobelts, nanoflowers, and nanostructures, and their performances as electrode materials in LIBs have been widely studied [13,[26][27][28][29][30][31][32][33].…”

TiO2(R)/VO2(M)/TiO2(A) multilayer film as smart window: Combination of energy-saving, antifogging and self-cleaning functions

“…[1,2] Smart windows have the potential to moderate the energy consumption of buildings, which is almost the equivalent of 30À40% of the primary energy used in worldwide. [3,4] Among the various types of chromogenic materials, thermochromic materials have attracted the attention of researchers and been the subject of extensive studies for applications to smart windows. [5][6][7] The most widely studied thermochromic material as smart window is VO 2 with the monoclinic (M) phase (shown as VO 2 (M)), which is able to execute a reversible transition at a phase-transition temperature (T c E68 1C): below T c the material is monoclinic, insulating and quite infrared transparent (VO 2 (M)), and above T c it is tetragonal, metallic and infrared reflecting (VO 2 (R)).…”

Durability of thermochromic VO2 thin films under heating and humidity: Effect of Al oxide top coatings

“…We also note that VO 2 -based nanoparticles may be of considerable interest for TC fenestration [11,[16][17][18]. Core-shell structures have been investigated recently with VO 2 cores surrounded by shells comprised of SiO 2 [44][45][46][47][48] or TiO 2 [49][50][51] and, again, the top layer may serve as oxidation protection. …”