A Universal Approach To Achieve High Luminous Transmittance and Solar Modulating Ability Simultaneously for Vanadium Dioxide Smart Coatings via Double-Sided Localized Surface Plasmon Resonances

Vanadium dioxide (VO2)-based thermochromic coatings has attracted considerable attention in the application of smart windows as a result of their intriguing property of metal–insulator transition at moderate temperatures. However, the practical requirements of smart windows, i.e., the high luminous transmittance of Tlum > 60% and large solar modulating ability of ΔTsol > 10%, are competing to a large extent and hardly satisfied simultaneously. Here, we proposed a facile and universal method to prepare VO2 coatings for exceeding the criteria above using double-sided localized surface plasmon resonances (LSPRs), which are excited by the VO2 nanoparticles dispersed evenly on both surfaces of the fused silica substrate. With subtle engineering of the sol–gel and heat treatment processes, the morphology of as-prepared VO2 nanoparticles and corresponding LSPRs are controlled to achieve a high luminous transmittance (Tlum = 68.2%) and solar modulating ability (ΔTsol = 11.7%) simultaneously. Further simulation suggests that the double-sided LSPRs can collectively enhance the performance of VO2 smart coatings. Moreover, the double-sided VO2 nanoparticle coatings demonstrate stable performance with no more than 1% degradation of Tlum and ΔTsol after 1500 cycles. This study provides an alternative strategy to obtain high-quality VO2 (M) solar modulating coatings.