Hydrothermal Synthesis of VO2 Polymorphs: Advantages, Challenges and Prospects for the Application of Energy Efficient Smart Windows.

Citation:

Li M, Magdassi S, Gao Y, Long Y. Hydrothermal Synthesis of VO2 Polymorphs: Advantages, Challenges and Prospects for the Application of Energy Efficient Smart Windows. SmallSmall. 2017;13 (36) :n/a.

Date Published:

2017///

Abstract:

Vanadium dioxide (VO2) is a widely studied inorg. phase change material, which has a reversible phase transition from semiconducting monoclinic to metallic rutile phase at a crit. temp. of τc ≈ 68 °C. The abrupt decrease of IR transmittance in the metallic phase makes VO2 a potential candidate for thermochromic energy efficient windows to cut down building energy consumption. However, there are three long-standing issues that hindered its application in energy efficient windows: high τc, low luminous transmittance (Tlum), and undesirable solar modulation ability (ΔTsol). Many approaches, including nano-thermochromism, porous films, biomimetic surface reconstruction, gridded structures, antireflective overcoatings, etc, have been proposed to tackle these issues. The first approach-nano-thermochromism-which is to integrate VO2 nanoparticles in a transparent matrix, outperforms the rest; while the thermochromic performance is detd. by particle size, stoichiometry, and crystallinity. A hydrothermal method is the most common method to fabricate high-quality VO2 nanoparticles, and has its own advantages of large-scale synthesis and precise phase control of VO2. This Review focuses on hydrothermal synthesis, phys. properties of VO2 polymorphs, and their transformation to thermochromic VO2(M), and discusses the advantages, challenges, and prospects of VO2(M) in energy-efficient smart windows application. [on SciFinder(R)]