Bioinspired Durable Daytime Radiative Cooling Wood: Realizing Outdoor Longtime Use

Daytime radiative cooling dissipates heat from surfaces by reflecting sunlight and emitting infrared radiation to outer space, featuring zero-energy consumption. Wood-based coolers have received more attention due to their high infrared emissivity, sustainability, and low cost. However, they often degrade under ultraviolet (UV) radiation exposure, resulting in a poor cooling efficiency. Herein, inspired by the structure-functionality relationship in Saharan silver ants, an outdoor durable cooling wood (DCW) is developed that achieves excellent comprehensive performance via the assembly of the photonic structure of Mica@TiO₂ on the structure of delignified wood, including both high solar reflectance (0.958), infrared emittance (0.95), mechanical strength (47 MPa), and UV resistance. The unique structure can prevent breaking of the C-O-C skeleton of wood under direct sunlight; the daytime cooling efficiency of DCW can maintain 4.5 °C after 720 h of UV exposure. This work paves the way for the development of durable daytime radiative cooling materials for energy savings.