He Jiajun, Zhang Qingyuan, Zhou Yaya, Chen Yu, Ge Haixiong, Tang Shaochun
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, People's Republic of China.
ACS Nano. 2024 Apr 30;18(17):11120-11129. doi: 10.1021/acsnano.3c12244. Epub 2024 Apr 16.
Passive radiative cooling (PRC) has been acknowledged to be an environmentally friendly cooling technique, and especially artificial photonic materials with manipulating light-matter interaction ability are more favorable for PRC. However, scalable production of radiative cooling materials with advanced biologically inspired structures, fascinating properties, and high throughput is still challenging. Herein, we reported a bioinspired design combining surface ordered pyramid arrays and internal three-dimensional hierarchical pores for highly efficient PRC based on mimicking natural photonic structures of the white beetle ' wings. The biological photonic film consisting of surface ordered pyramid arrays with a bottom side length of 4 μm together with amounts of internal nano- and micropores was fabricated by using scalable phase separation and a quick hot-pressing process. Optimization of pore structures and surface-enhanced photonic arrays enables the bioinspired film to possess an average solar reflectance of ∼98% and a high infrared emissivity of ∼96%. A temperature drop of ∼8.8 °C below the ambient temperature is recorded in the daytime. Besides the notable PRC capability, the bioinspired film exhibits excellent flexibility, strong mechanical strength, and hydrophobicity; therefore, it can be applied in many complex outdoor scenarios. This work provides a highly efficient and mold replication-like route to develop highly efficient passive cooling devices.
被动辐射冷却（PRC）已被公认为是一种环保的冷却技术，特别是具有操纵光与物质相互作用能力的人工光子材料对被动辐射冷却更为有利。然而，可扩展地生产具有先进生物启发结构、迷人特性和高通量的辐射冷却材料仍然具有挑战性。在此，我们报道了一种受生物启发的设计，该设计结合了表面有序金字塔阵列和内部三维分级孔隙，用于基于模仿白甲虫翅膀的自然光子结构的高效被动辐射冷却。通过可扩展的相分离和快速热压工艺制备了由底面边长为4μm的表面有序金字塔阵列以及大量内部纳米孔和微孔组成的生物光子薄膜。孔隙结构和表面增强光子阵列的优化使这种受生物启发的薄膜具有约98%的平均太阳反射率和约96%的高红外发射率。在白天记录到比环境温度低约8.8°C的温度下降。除了显著的被动辐射冷却能力外，这种受生物启发的薄膜还表现出优异的柔韧性、强大的机械强度和疏水性；因此，它可应用于许多复杂的户外场景。这项工作为开发高效被动冷却装置提供了一条高效且类似模具复制的途径。
