Photoluminescent radiative cooling for aesthetic and urban comfort

Passive radiative cooling offers a sustainable solution to reduce carbon emissions in space cooling by simultaneously reflecting sunlight and emitting thermal radiation. However, the super-white property of conventional passive radiative cooling materials poses challenges for large-scale urban applications by conflicting with aesthetic requirements and neglecting impacts on urban microclimate and pedestrian thermal and visual comfort. Here inspired by the biological photoadaptation of coral, we present photoluminescence-based aesthetic composites as innovative urban skins that harness the enhanced light conversion of rare-earth-doped phosphors while decoupling from light-scattering-based whiteness, providing cool colours with improved urban compatibility. These composites demonstrate effective spectral reflectance of over 100% and peak reflectance up to 141% in their emission regions, despite a moderate overall solar reflectance (90.2-93.2%). With vivid yet angle-insensitive green, yellow and red appearances, the composites achieve subambient temperature reductions of 2.2-3.7 degrees C compared with ambient air and 6.1-7.9 degrees C relative to their non-photoluminescent counterparts. Moreover, their moderate whiteness alleviates excessive thermal and visual stress induced by trapping of sunlight in urban environments. Featuring excellent durability, compatibility and stability, these composites offer a scalable solution for energy-efficient and aesthetically pleasing radiative cooling in architecture, textiles and beyond, advancing passive radiative cooling technologies towards diverse real-world implementations.