Low infrared emissivity and oxidation stability of Ti3C2T MXene-based composite with tannic acid

As a novel material with low infrared emissivity, Ti3C2Tx MXene is promising in infrared stealth. However, the problem that MXene is easily oxidized poses a great challenge to its practical applications. In this paper, a tannic acid (TA) enhanced MXene oxidation stability composite film with low infrared emissivity is reported. TA effectively diminishes the pore size within the MXene film and leads to a tight and orderly arrangement of nanosheets, maintaining the low emissivity properties of Ti3C2Tx MXene itself. In addition, TA reacts preferentially with H2O/O2 entering the film to consume the oxidizing source, while also being able to form coordination with Ti atoms for protection against oxidation, resulting in the composite film exhibiting excellent oxidation resistance. Remarkably, there is no formation of TiO2 and the emissivity only rises from 0.16 to 0.18 after 72 h in the humid heat environment. Even after prolonged exposure to 20-day humid heat, it still maintains exceptional infrared emissivity (0.24) and stealth performance (reducing the radiant temperature of the object from 94℃ to 47.4℃, △T = 46.6℃). In contrast, the original Ti3C2Tx MXene film has lost its infrared stealth performance after 10-day humid heat (△T = 5.3℃) with an infrared emissivity of 0.76. This paper provides a new strategy to solve the problem of MXene performance stability in humid and oxidizing environments.