Stepless IR Chromism in Ti3 C2 Tx MXene Tuned by Interlayer Water Molecules

• Published in: Advanced materials (Weinheim) Vol. 36; no. 7; p. e2308189
• Main Authors: Li, Keqiao, Lin, Chongjia, Liu, Gongze, Wang, Guang, Ma, Wei, Li, Meng, Li, Yang, Huang, Baoling
• Format: Journal Article
• Language: English
• Published: 01.02.2024
• ISSN: 1521-4095
• DOI: 10.1002/adma.202308189

Real-time control over infrared (IR) radiation of objects is highly desired in a variety of areas such as personal thermal regulation and IR camouflage. This requires the dynamic modulation of IR emissivity in a stepless manner over a wide range (>50%), which remains a daunting challenge. Here, an emissivity modulation phenomenon is reported in stacked 2D Ti3 C2 Tx MXene nanosheets, from 12% to 68% as the intercalation/discharging of water molecules within the interlayers. The intercalation of water molecules dynamically changes the electronic properties and the complex permittivity in IR frequencies of Ti3 C2 Tx . This emissivity modulation is a stepless and reversible process without the assistance of any external energy input. Further, intercalating cellulose nanofibers into the Ti3 C2 Tx interlayers makes this dynamic process highly repeatable. Last, a sweat-responsive adaptive textile that can improve thermal comfort of human body under changes in metabolic rates and environmental conditions is demonstrated, showing great potential of this mechanism in passive on-demand radiation modulation.