Textiles with passive radiative cooling (PRC)/passive radiative heating (PRH) capabilities have been developed to address human thermal comfort in different climate scenarios. Although materials with single PRC/PRH function have been reported, they tended to exhibit only one function of either cooling or heating, which was restrictive in achieving efficient and controllable personal thermal management. Herein, we propose a dual-mode Janus film composed of a PVDF-HFP/ZrO cooling layer and a Mxene/CNT heating layer for efficient all-day PRC/PRH. Owing to the natural high refractive index of ZrO nanoparticles and the strong scattering of sunlight by the PVDF-HFP nanofibers, the cooling side exhibits a high solar reflectance of 97.1 %. With an infrared emittance of 93 % in atmospheric window, the cooling side achieves subambient cooling temperatures of 8.8 °C during daytime and 7 °C during nighttime. Meanwhile, the Mxene/CNT synergy enables the heating side to exhibit high solar absorbance and electrical conductivity, resulting in a significant PRH capability of up to 19 °C and an outstanding active Joule heating capability as a temperature compensation. The dual-mode Janus film is able to switch cooling/heating modes by simply flipping the interface to alter the sky-facing side, enabling efficient and continuous personal thermal management in complex and changeable environments.

中文翻译：

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Janus 薄膜耦合辐射冷却和加热，用于全天主动/被动个人热管理


具有被动辐射冷却（PRC）/被动辐射加热（PRH）功能的纺织品已被开发出来，以解决不同气候情况下的人体热舒适问题。虽然具有单一 PRC/PRH 功能的材料已有报道，但它们往往只表现出冷却或加热一种功能，这限制了实现高效、可控的个人热管理。在此，我们提出了一种由 PVDF-HFP/ZrO 冷却层和 Mxene/CNT 加热层组成的双模式 Janus 薄膜，可实现高效的全天 PRC/PRH。由于ZrO纳米粒子的天然高折射率和PVDF-HFP纳米纤维对太阳光的强烈散射，冷却侧表现出高达97.1%的太阳光反射率。大气窗口红外发射率为93%，制冷侧白天可实现低于环境温度8.8°C，夜间可达到低于环境温度7°C。同时，Mxene/CNT协同作用使加热侧表现出高太阳能吸收率和电导率，从而实现高达19°C的显着PRH能力和出色的主动焦耳加热能力作为温度补偿。双模Janus薄膜能够通过简单翻转界面改变面向天空的一侧来切换制冷/制热模式，从而在复杂多变的环境中实现高效、持续的个人热管理。