Nano-SiO2 aerogel reinforced ultraviolet coating of woodenware for daytime radiative cooling

Ultraviolet (UV) coatings for woodenware (UVCW) are widely applied in home furnishings, building materials, and interior decoration because of their rapid curing, high hardness, and low volatile organic compound (VOC) emissions. However, conventional UVCW lack passive daytime radiative cooling capability, restricting their use in energy-efficient applications. Herein, this work enhances the daytime radiative cooling performance of UVCW by incorporating nano-SiO2 aerogel via direct blending method. The physicochemical properties and outdoor daytime radiative cooling effects of the UVCW before and after nano-SiO2 aerogel reinforcement were comprehensively evaluated. Unlike conventional UVCW or SiO2 nanoparticle coatings, this approach achieves an ultrahigh infrared emissivity of 94.95% in the 8–13 μm atmospheric window without complex multilayer structures. As a result, the nano‑SiO2 aerogel reinforced UVCW realizes an average daytime temperature reduction of 6.4 °C outdoors, with a maximum cooling reduction of 10.4°C. This study not only demonstrates the potential for imparting passive daytime radiative cooling functionality to wood‑based materials but also provides a facile, scalable, and energy‑efficient strategy for developing advanced radiative cooling coatings.