Radiative cooling materials: recent advances in preparations, applications, challenges and opportunities.

Radiative cooling is an emerging technology for passive cooling. This technology relies on the optical properties of the material itself to dissipate heat to the outside, achieving passive cooling without energy consumption. The energy of an object can be radiated into the depths of the universe through atmospheric windows (8-13 μm). Therefore, radiative cooling, as a cooling technology that does not require energy input, can provide a new idea for addressing the global climate crisis. In this paper, the commonly used cooling materials are introduced and summarized in terms of preparation, structure, and properties of the materials. The cooling properties of various materials are analyzed. The application of micro-nano doped materials and polymer materials in building cooling, atmospheric water collection and personal thermal management, etc. is introduced. In addition, a comprehensive discussion is conducted on the future development prospects and challenges faced by radiative cooling technology.