He Jiajun, Chen Yu, Guo Rui, 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, P. R. China.
ACS Nano. 2025 Aug 26;19(33):30361-30370. doi: 10.1021/acsnano.5c09133. Epub 2025 Aug 15.
Passive daytime radiative cooling (PDRC) has been considered an effective zero-power cooling method, and colored PDRC films can efficiently avoid glare effects as well as expand aesthetic and functional demands. However, the spectral designs of most colored radiative coolers are complex, and they have shortcomings in adaptability to weather changes due to static optical properties. It remains a great challenge to develop self-adaptive colored radiative coolers for all-humidity efficient radiative cooling and to expand moisture-responsive applications. Herein, based on the bionic concept derived from the color-changing characteristic of chameleons in response to environmental conditions, an insight into humidity-driven dynamically reversible dual-band spectral regulation is proposed. Humidity-sensitive colored film (HSCF) possessing spectral self-regulation abilities across both solar and mid-infrared wavelength ranges is developed, which shows dynamically enhanced solar reflection and mid-infrared emissivity as ambient humidity increases. Outdoor tests demonstrate that the obtained colored film can achieve self-adaptive efficient PDRC over a wide ambient humidity range (25-90%) throughout the whole day. More importantly, the dynamic dual-band regulation process is autonomous, energy-free, and reversible. This work provides a route to develop self-adaptive colored radiative coolers for application in all humidity conditions.
被动式日间辐射冷却（PDRC）被认为是一种有效的零功率冷却方法，而彩色PDRC薄膜既能有效避免眩光效应，又能拓展美学和功能需求。然而，大多数彩色辐射冷却器的光谱设计复杂，且由于其静态光学特性，在适应气候变化方面存在不足。开发适用于全湿度高效辐射冷却的自适应彩色辐射冷却器并拓展湿度响应应用仍然是一个巨大的挑战。在此，基于从变色龙响应环境条件的变色特性衍生出的仿生概念，提出了一种对湿度驱动的动态可逆双波段光谱调控的见解。开发了一种在太阳和中红外波长范围内都具有光谱自调节能力的湿度敏感彩色薄膜（HSCF），它在环境湿度增加时表现出动态增强的太阳反射率和中红外发射率。户外测试表明，所制备的彩色薄膜在全天的宽环境湿度范围（25%-90%）内都能实现自适应高效PDRC。更重要的是，动态双波段调控过程是自主、无能耗且可逆的。这项工作为开发适用于所有湿度条件的自适应彩色辐射冷却器提供了一条途径。
