Scalable room-temperature manufactured W-VO2 smart windows: Enhancing multi-scale performance of building

Thermochromic smart windows based on vanadium dioxide (VO2) offer a promising passive approach for reducing building solar heat gain by selectively modulating near-infrared radiation. However, their large-scale application is limited by complex fabrication processes and nanoparticle agglomeration. Herein, a scalable room-temperature ultraviolet (UV) photocuring strategy is developed to fabricate W–VO2 thermochromic films. By introducing an A-DCP monomer, rapid UV-induced polymerization forms a dense three-dimensional crosslinked network within seconds, enabling effective in-situ confinement and suppressing nanoparticle migration and aggregation. Structural and spectral analyses confirm the preserved VO2(M) phase and improved microstructural uniformity. At the optimal W–VO2 content of 1.0 wt%, this film achieved a high ΔTsol of 15.04% while maintaining a Tlum of approximately 35%, and exhibited excellent color stability during the thermochromic conversion process. Furthermore, an application-oriented multi-scale evaluation framework is established to correlate microstructure, optical modulation, visual perception, and building-scale energy performance. Scaled building-model experiments under 680 W m−2 irradiation show a steady-state indoor temperature reduction of 7.03 °C compared with clear glass. EnergyPlus simulations across nine climate zones demonstrate significant annual energy-saving potential, reaching 24.13% in Vancouver and 23.59% in Riyadh.