Low infrared emitter from Ti3C2T MXene towards highly-efficient electric/solar and passive radiative heating

Realizing all-day and all-weather energy-saving heating is crucial for mitigating the global energy and ecology crisis. Electric/solar heating are two promising heating approaches, yet materials with high electrical conductivity, high solar absorptivity, and low infrared emissivity at the same time are rare in nature, which are highly anticipated and of great significance for highly efficient electric/solar heating. In this work, we demonstrate that Ti3C2Tx MXene with low IR emissivity (14.5%) fills the gap in the absence of the above materials, exhibiting a remarkable electric/solar heating performance. The saturated heating temperature of Ti3C2Tx film reaches a record-high value of 201 °C at a low driving voltage of 1.5 V, and reaches 84.3 °C under practical solar irradiation (750 W/m2) with a high solar to the thermal conversion efficiency of 75.3%, which is far superior to other reported materials. Meanwhile, the low IR emissivity endows Ti3C2Tx with a remarkable passive radiative heating capability of 7.0 °C, ensuring zero-energy heating without electric/solar energy supply. The intrinsic characteristic of high electrical conductivity, high solar absorptivity, and low IR emissivity makes Ti3C2Tx unique existence in nature, which is highly promising for all-day and all-weather energy-saving heating.