Passive daytime radiative cooling (PDRC) technology provides a promising path for combating global climate warming. Natural photonic structures with efficient radiative cooling performance exist in Saharan silver ants, enabling them to cater to extremely hot weather in the desert. However, previously reported bioinspired structured coolers are easily dampened by environmental aging and contamination, making cooling ineffective. Herein, a bioinspired binary hybrid (Bio-BH) film fabricated via drop casting and unidirectional rubbing methods is presented. The Bio-BH film possesses resonant hollow particles inside the polymer and a nano/microscale photonic structure on the surface composed of a triangular prism array and nanospheres uniformly atop the array, exhibiting high solar reflectance (0.93) and enhanced thermal emissivity (0.94). A temperature drop of ∼6.9 °C is achieved at noon under direct sunlight. Moreover, after fluoride treatment, the dual-scale rough surface endows the film with superhydrophobicity of a water contact angle (WCA) of ∼157°. Combining self-cleaning and durable capacities, this work will pave the way for long-term PDRC performance in real-world application scenarios.

中文翻译：

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用于白天辐射冷却的二元协同光子结构的仿生设计

被动日间辐射冷却（PDRC）技术为应对全球气候变暖提供了一条有希望的途径。撒哈拉银蚁具有具有高效辐射冷却性能的天然光子结构，使它们能够适应沙漠中极其炎热的天气。然而，之前报道的仿生结构冷却器很容易受到环境老化和污染的影响，从而导致冷却效果不佳。在此，提出了一种通过滴铸和单向摩擦方法制造的仿生二元杂化（Bio-BH）薄膜。 Bio-BH薄膜在聚合物内部具有共振中空颗粒，表面具有由三角棱柱阵列和均匀分布在阵列顶部的纳米球组成的纳米/微米级光子结构，表现出高太阳反射率（0.93）和增强的热发射率（0.94）。中午在阳光直射下，气温下降约 6.9 °C。此外，经过氟化处理后，双尺度粗糙表面赋予薄膜水接触角（WCA）~157°的超疏水性。这项工作结合了自清洁和耐用能力，将为 PDRC 在实际应用场景中的长期性能铺平道路。