Overcooling-preventive electrospun film doped with W-VO2 nanoparticles for dynamic radiative cooling

Radiative cooling is an emerging green technology in which an object naturally cools down through radiation heat transfer without any energy consumption. However, it induces overcooling at cold nights or in winters. This hinders its potential applications in various scenarios like residential buildings and clothing. Here, an overcooling-preventive radiative cooling film was prepared using electrospinning, incorporating tungsten doped vanadium dioxide nanoparticles into a poly(vinylidene fluoride-hexafluoropropylene) matrix. Experiments and simulations have proved that it can automatically weaken the radiative cooling function below the critical temperature, thus avoiding overcooling. The nighttime temperature drop induced by the film was 3.8 °C, while the counterpart was 6.5 °C, with an automatic tuning of 42 %. Simulations reveal that the film is applicable at different geographical regions under various climatic conditions. The composite film can be applied in clothing, curtains, tentages, and car covers to improve thermal comfort and health of users, and is conducive to energy conservation and carbon reduction of the society.