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.