Direct and continuous hydrothermal flow synthesis of thermochromic phase pure monoclinic VO₂ nanoparticles

Abstract

The first direct synthesis of pure thermochromic VO2(M) nanoparticles with particle sizes below 50 nm by continuous hydrothermal flow synthesis (CHFS).

Toward Room-Temperature Thermochromism of VO2 by Nb Doping: Magnetic Investigations

“…Malarde et al (14) used a continuous hydrothermal flow synthesis (CHNF) process to synthesize VO 2 and Nbdoped VO 2 nanoparticles (NPs), with particle sizes in the range of 50-200 nm. Pulsed laser deposition (PLD) (15) and aerosol-assisted chemical vapor deposition (AACVD) methods (16) are also reported to directly grow Nbdoped VO 2 films.…”

Thermochromic Behavior of VO2/Polymer Nanocomposites for Energy Saving Coatings

“…Moreover, most of these growth techniques, although they are of high fidelity and can produce good quality thermochromic VO 2 films, demand high deposition temperatures (>400 • C) [11,[14][15][16][17][18], with very few employing sputtering techniques between 250 and 300 • C [12,13,[19][20][21], making it impossible to utilize flexible (polymeric) substrates.Another approach, called the ex-situ approach [22], to the fabrication of VO 2 thermochromic films is to first synthesize the desired material as a powder and then to deposit the material as a film onto the desired surface. Thermochromic VO 2 in the form of powders have been synthesized by various methods, such as thermolysis [23,24], rapid thermal annealing [25], pyrolysis [26], and, the most utilized method, hydrothermal (solvothermal) synthesis [27][28][29][30][31]. The latter is the most promising due to the high crystallinity of the resulting products, the precise phase control, the versatility on the synthetic parameters, and the possibility of large-scale synthesis [32].In order to transform the powder into film, various deposition methods have been applied, most notably sol-gel methods.…”

“…Another approach, called the ex-situ approach [22], to the fabrication of VO 2 thermochromic films is to first synthesize the desired material as a powder and then to deposit the material as a film onto the desired surface. Thermochromic VO 2 in the form of powders have been synthesized by various methods, such as thermolysis [23,24], rapid thermal annealing [25], pyrolysis [26], and, the most utilized method, hydrothermal (solvothermal) synthesis [27][28][29][30][31]. The latter is the most promising due to the high crystallinity of the resulting products, the precise phase control, the versatility on the synthetic parameters, and the possibility of large-scale synthesis [32].…”

Chemical vapor deposition and temperature-dependent Raman characterization of two-dimensional vanadium ditelluride

“…The binding energies of V 2p 3/2 and V 2p 1/2 are 513.1 eV and 520.7 eV respectively are near to those in 1T-VS 2 and 1T-VSe 2 [31][32][33][34] and lower than that in VO 2 . 35 The binding energies of Te 3d 5/2 and Te 3d 3/2 are 573.3 eV and 583.7 eV respectively comparable to the oxidation state of Te. In VTe 2 , the binding energy difference (DE) between V 2p 3/2 and Te 3d 5/2 is 60.2 eV, which is near to that of V and Te primary substance (60.7 eV), demonstrating that the V-Te bonds in VTe 2 are weak because of the small electronegativity difference between V and Te.…”