Passive daytime radiative cooling (PDRC) is a

promising practice to realize sustainable thermal management with

no energy and resources consumption. However, there remains a

challenge of simultaneously integrating desired solar reflectivity,

environmental durability, and mechanical robustness for polymeric

composites with nanophotonic structures. Herein, inspired by a

classical armor shell of a pangolin, we adopt a generic design

strategy that harnesses supramolecular bonds between the TiO2-

decorated mica microplates and cellulose nanofibers to collectively

produce strong interfacial interactions for fabricating interlayer

nanostructured PDRC materials. Owing to the strong light

scattering excited by hierarchical nanophotonic structures, the

bioinspired film demonstrates a desired reflectivity (92%) and

emissivity (91%) and an excellent temperature drop of 10 °C

under direct sunlight. Notably, the film guarantees high strength (41.7 MPa), toughness (10.4 MJ m?3), and excellent environmental

durability. This strategy provides possibilities in designing polymeric PDRC materials, further establishing a blueprint for other

functional applications like soft robots, wearable devices, etc.