A multi-mode cellulose acetate/MXene Janus film with structure enhanced self-reflection, selective emission and absorption for cooling and heating

Passive radiative thermal management has been recognized as one of the most promising energy-saving technologies to provide thermal comfortable environment. However, static function and complex production process limit its application. Herein, we propose a simple strategy to achieve the integration of radiative cooling, radiative heating, and active electro-thermal heating. It is worth stressing that the radiative cooling is only based on the self-reflective structure and self-emissive molecular property of cellulose acetate electrospun membrane. In cooling mode, the average temperature of Janus film outdoor is 9.4 °C lower than commercial cotton fabric. Meanwhile, radiative heating and active heating stem from the photothermal and electrothermal performance of MXene . In heating mode, the average temperature of Janus film is 40 °C higher than cotton fabric. Flipping the Janus film allows for dynamic thermal management. In short, the scalable and universal strategy paves the way for the development of dynamic thermal-regulating technology.