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.