New pathway for global carbon neutrality: Radiative cooling

Massive greenhouse gas emissions have induced the rise of global temperature and climatic anomalies, significantly threatening the existence of life on the Earth. Hence, a new strategy is urgently needed to save and reduce emission to protect our living environment and achieve carbon neutrality visions. However, some are limited by complex systems, geographical, environmental and stability issues.

Therefore, in response to and global carbon neutrality, there is an immediate need for new cooling technologies in sustainable carbon-neutral models to confront the issue of superheating as an against the energy challenge.

To cope with these challenges, the research team led by Prof. Guangming Tao (Wuhan National Laboratory for Optoelectronics and Optics Valley Laboratory, Huazhong University of Science and Technology) and Prof. Cheng-Wei Qiu (Department of Electrical and Computer Engineering, National University of Singapore) has proposed a potential radiative cooling paradigm based on structural and material design, and new opportunities for sustainable carbon neutrality as a zero-energy, ecologically friendly cooling strategy have also been presented.

(a) Theoretical framework to design IR-transparent fabric. (b) Schematic of polydopamine and nano-porous polyethylene (PDA-NanoPE-mesh) with performance comparable with that of cotton. (c) Diagram of face masks with electrospun nylon-6 nanofibers on needle-punched nanoPE substrate. (d) Schematic of nanoPE fabric with high mid-IR transparency, visible opacity and good wearability. (e) ZnO NPs embedded nano-porous PE fabric. (f) Schematic for the coloration of radiative cooling textiles, which is made by mixing IR-transparent inorganic pigment nanoparticles with PE. (g) Direct radiative cooling using IR-selective transparent covers. (h) Schematic of highly IR-transparent PE bubble warp to block ambient convective heat transfer and ensure the radiative heat transport from objects to outer space. (i) The selection of functional groups for high emittance and low solar absorption. Credit: Science China Press

(a) Diagram of coating a metal surface with cheap plastic materials. (b) Enhanced convection of air beneath the black robes carries this heat away before it reaches the skin making it just as effective as the white robes. (c) Diagram of ultra-broadband metal-dielectric photonic structures. (d) Diagram of HfO2-SiO2 photonic film. (e) Diagram of visibly transparent silica photonic crystal. (f) Diagram of the scalable-manufactured glass-polymer hybrid metamaterial. (g) Diagram of hierarchically porous polymer coatings. (h) Diagram of the cooling wood structure. (i) A schematic diagram of the planar PDMS/metal thermal emitter. (j) Artificially fabricated radiative coolers based on the fluff structure of N. gigas. (k) Effective scattering diagram of micro- and nano-structures of the es-PEO film. (l) Hierarchical-morphology metafabric for scalable radiative cooling. (m) Diagram of the intrinsic molecular vibrations and porous structure of the cellulose acetate (CA) film. Credit: Science China Press

Radiative cooling is applied in a series of everyday life and extreme scenarios. Credit: Science China Press