Enhanced Thermochromic Performance of VO(2) Nanoparticles by Quenching Process

Vanadium dioxide (VO(2)) has been a promising energy-saving material due to its reversible metal-insulator transition (MIT) performance. However, the application of VO(2) films has been seriously restricted due to the intrinsic low solar-energy modulation ability (ΔT(sol)) and low luminous transmittance (T(lum)) of VO(2). In order to solve the problems, the surface structure of VO(2) particles was regulated by the quenching process and the VO(2) dispersed films were fabricated by spin coating. Characterizations showed that the VO(2) particles quenched in deionized water or ethanolreserved VO(2)(M) phase structure and they were accompanied by surface lattice distortion compared to the pristine VO(2). Such distortion structure contributed to less aggregation and highly individual dispersion of the quenched particles in nanocomposite films. The corresponding film of VO(2) quenched in water exhibited much higher ΔT(sol) with an increment of 42.5% from 8.8% of the original VO(2) film, because of the significant localized surface plasmon resonance (LSPR) effect. The film fabricated from the VO(2) quenched in ethanol presented enhanced thermochromic properties with 15.2% of ΔT(sol) and 62.5% of T(lum). It was found that the excellent T(lum) resulted from the highly uniform dispersion state of the quenched VO(2) nanoparticles. In summary, the study provided a facile way to fabricate well-dispersed VO(2) nanocomposite films and to facilitate the industrialization development of VO(2) thermochromic films in the smart window field.