Development of an Inorganic Weather-Resistance Composite Fabric for Efficient Passive Daytime Radiative Cooling Applications

In this study, a flexible inorganic silica nanofiber membrane was developed. This weather resistant fabric has excellent passive radiation cooling capabilities. It possesses abundant silica-air contact surfaces and Si-O bonds, leading to high solar spectral reflectance and mid-infrared spectral emissivity. Under direct sunlight, flexible inorganic silica nanofiber membrane achieves a temperature reduction of 7-8 °C compared to a control without relying on silver or aluminum foils as background layers, yielding an average radiative cooling power density of 66 W/m². Through the electrospinning preparation process, the prepared nanofiber membrane has good flexibility and can be applied to passive heat dissipation applications on the surfaces of buildings. Unlike photonic crystals, organic membranes, and coatings, flexible inorganic silica nanofiber membranes are characterized by a simple, cost-effective, and scalable production process, offering durability and efficiency for mass production. This work introduces a novel fabrication method for inorganic radiative coolers, providing new insights into achieving enhanced daytime passive radiative cooling performance by using inorganic materials.