Electrons-Donating Derived Dual-Resistant Crust of VO₂ Nano-Particles via Ascorbic Acid Treatment for Highly Stable Smart Windows Applications

Abstract

Traditional vanadium dioxide (VO 2 ) material faced severe challenges of low stability in acid, humid, and oxygenic environments, which hinder its real applications. Here, we report a facile improving process which can enhanced the stability of VO 2 nanocrystals in the environments above. Ascorbic acid (AA), as an important antioxidant for organism in medicine and biology, was ingeniously used for enhancing the antioxidation abilities of inorganic material. At the same time, the AA could generate the hydrogen doping occurred on the surface of VO 2 nanocrystals, which enhanced their Antiacid abilities simultaneously. The AA treated VO 2 nanocrystals retain stable in H 2 SO 4 and H 2 O 2 solution and exhibit high durability in hyperthermal (60 °C) and humid (90%) environment. Characterizations and first-principles theoretical calculations confirmed that the coordination of ascorbic acid molecules on VO 2 nanocrystals induced charge-carrier density reorganization and protons transferring electrostatically. Then the formed H x VO 2 provides an enhancing formation energy for oxygen vacancy and protects the particles from corrosion. This work is beneficial to the VO 2 nanoparticles coated and decorated processes and exhibit good potential for practical application of VO 2 -based smart windows.

VO2/ZnO bilayer films with enhanced thermochromic property and durability for smart windows

“…And the contact between ZnO layer and VO2 layer would make the electrons transfer through the interface, leading to the increase of electrons in the VO2 layer. The transfer electrons not only drive the protons into VO2 but also enhance the formation energy for oxygen vacancy which is positive charged, thereby delay the oxidization of VO2 [37][38][39]. In order to account for the stability of VO2/ZnO bilayer film, XPS characterization was carried out.…”

Challenges and Opportunities toward Real Application of VO2-Based Smart Glazing

“…, because of the acidic and oxidative environment. 105,106 Moreover, the reaction products are much easier to run off from the surface than pristine VO 2 films, which implies that these products are more convenient to make contact with and poison people. Therefore, it is necessary to study the toxicity of these additional reaction products.…”

Facile Solution Process of VO2 Film with Mesh Morphology for Enhanced Thermochromic Performance

“…However, the additional protective layer always leads to the deteriorated optical performance of VO 2 film with reduced solar modulation efficiency. Recently, ascorbic acid was used to process the VO 2 surface to enhance its antioxidation and anti-acid properties [34]. An acid solution was utilized to etch pristine VO 2 film prepared with magnetron sputtering to produce a karst landforms-like structure so that the solar modulation efficiency and visible transmittance were improved simultaneously [35].…”