Novel synthesis of pure VO₂@SiO₂ core@shell nanoparticles to improve the optical and anti-oxidant properties of a VO₂ film

Abstract

A novel moderately surfactant-free strategy for the synthesis of pure VO2@SiO2 core@shell nanoparticles to improve the optical and anti-oxidant properties of VO2 particles, which involves potential interface chemistry.

New intelligent multifunctional SiO2/VO2 composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity

“…NIRSE was reduced by about 47.6% for the uncoated VO 2 films, whereas it changed slightly in SiO 2 /VO 2 composite films. Evidently, VO 2 films underwent vanadium oxide reaction and were oxidized to V 2 O 5 or other high valence vanadium oxides in air [ 12 ]. VO 2 particles can be effectively prevented from being oxidized to other high valence vanadium oxides by adding a layer of SiO 2 on the VO 2 film as a barrier layer for oxygen diffusion.…”

“…VO 2 is the first choice as material for intelligent temperature control due to the abrupt change in its optical properties before and after phase change. However, the main obstacles to the large-scale application of VO 2 films include decreasing phase transition temperature [ 7,8 ], enhancing visible light transmittance [ 9 ], increasing solar conditioning capacity [ 10 ] under strong visible light absorption conditions [ 11 ], and maintaining long-term stability upon exposure to air for a long period [ 12,13 ] or under high temperatures (above 300 °C) [ 14 ].…”

“…The reinforcement layer, which can also be called anti-reflective layer, is mainly designed to increase the transmittance of light [ 29 ] and improve anti-oxidation and anti-acid properties [ 30 ]. TiO 2 [ 31 ], SiO 2 [ 12 ], and ZrO 2 [ 32 ] are the primary anti-reflective layers used. The low visible light transmittance of VO 2 thin films is mainly due to their intrinsic absorption and light reflection.…”

Thermochromic VO2−SiO2 nanocomposite smart window coatings with narrow phase transition hysteresis and transition gradient width

“…Improvements to luminous transmittance can be achieved by suppressing reflection of visible light with anti-reflective multilayer systems [7,8,9,10,11,12,13] or graded index nanostructures [14,15] however this adds to the complexity of design. Alternative methods to improve the optical performance in a single coating step are composite films comprised of VO 2 nanoparticles embedded in a dielectric matrix [16,17,18,19,20]. The low density and sub-wavelength dimensions of vanadium dioxide domains means that visible reflectance is minimal.…”

Elucidating the Crystallite Size Dependence of the Thermochromic Properties of Nanocomposite VO2 Thin Films

“…The optical performance of our NS samples is indeed comparable to other recently reported values for VO 2 composite films where considerable effort has been made to reduce light scattering. 44,45,66,72−74 Zhang et al 45 and Miao et al 66 reduced Mie scattering by decreasing the as-synthesized VO 2 particle size through grinding or ball-milling treatments and achieved a T lum of 62.1% with Δ T sol of 12.4% and a T lum of 38.5% with Δ T sol of 16.9%, respectively. Guo et al have prepared ultrafine VO 2 nanoparticles using a unique one-step hydrothermal reaction in a self-released oxidizing atmosphere at relatively low temperatures and reported a T lum of 54.26% and a Δ T sol of 12.34%.…”