Li M, Magdassi S, Gao Y, Long Y. Hydrothermal Synthesis of VO
2 Polymorphs: Advantages, Challenges and Prospects for the Application of Energy Efficient Smart Windows.
SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017;
13:1701147. [PMID:
28722273 DOI:
10.1002/smll.201701147]
[Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 06/03/2017] [Indexed: 06/07/2023]
Abstract
Vanadium dioxide (VO2 ) is a widely studied inorganic phase change material, which has a reversible phase transition from semiconducting monoclinic to metallic rutile phase at a critical temperature of τc ≈ 68 °C. The abrupt decrease of infrared 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 determined 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, physical 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.
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