Structural rod-like particles for highly efficient radiative cooling

Passive daytime radiative cooling (PDRC) has attracted tremendous interest for the merit of zero energy consumption and free-pollution. While state-of-the-art PDRC techniques are still confined to specific application scenarios for the limited applicability and non-ideal environmental stability. We report an unconventional method of devising structural rod-like particle (RLP) with the textured surface embedding random nanopores for fabricating highly efficient radiative cooling coating. Our structural particle coating (SPC) containing the RLPs exhibits ultrahigh solar reflectance (97%) and long wave thermal emittance (95%), contributing to optimal average sub-ambient temperature drop of 5.7 °C in the nighttime and 4.3 °C in the daytime under solar intensity of nearly 1000 W/m2. It is a noteworthy finding because our SPC possesses paint-like simple structure and process, straightforward manufacturability, and offers a promising route for terrestrial radiative cooling. The superb insensitivity to space extreme temperature, high-energy electron irradiation and ultraviolet endows our SPC with even potential application under harsh space conditions.