Antireflective Core−Shell Composite Films with Switchable Radiation Properties for Passive Thermal Management of Glass Greenhouses

Abstract Greenhouses face significant energy losses due to their transparent exterior structures, and achieving both high light transmittance and dynamic thermal regulation remains a challenge. In this study, we developed a light-transmitting, temperature-responsive dynamic radiative film based on a W-VO2@SiO2 core−shell structure, capable of enabling passive thermal management at the greenhouse scale. The film exhibits a high transmittance of 0.92 in the 0.3−2.5 μm wavelength range, while its emissivity can be dynamically switched: it reaches 0.92 at high temperatures to enable radiative cooling, and remains at 0.80 at low temperatures to minimize heat loss. The key optical parameter modulation capabilities are Δε = 0.12 and ΔTsol = 0.2. Field tests achieved an average temperature reduction of 6.9 °C in summer and an increase of 6.4 °C in winter. Combined with greenhouse modeling and EnergyPlus simulations, energy savings of up to 356.9 MJ/m2 are projected for typical low-latitude regions. This study employs a nano-storm synthesis and solution-coating process that requires no vacuum or high-temperature annealing throughout the entire process, offering low-cost, large-scale manufacturing potential. It simultaneously optimizes light transmittance and adaptive thermal regulation performance, providing a system-level engineering solution for sustainable greenhouse operations.