Fig. 12
a Schematic diagram of atomic structure of multilayer MXene before and after water absorption [206]. Copyright 2020, Springer US. b Structural changes of MXene materials in low-humidity and high-humidity environments [207]. c Variation of resistance of MXene materials in different humidity environments [207]. Copyright 2019, American Chemical Society. d Spring-like helical core-sheath polyester yarn-based flexible MXene sensing structure [206]. e Variation of resistance with respect to the RH for the flexible MXene sensor [206]. f The effects of humidification and drying on resistance, which demonstrate the recoverability of the sensing performance and the reusability of the structure [206]. Copyright 2020, Springer US. g Schematic diagram of the synthesis of S- Ti3C2Tx MXene K2Ti4O9 composite [208]. h Variation of resistance with different RH [208]. i Response comparison of different humidity [208]. Copyright 2021, Elsevier. j The synthesis process of Ti3C2Tx/TiO2 composite [209]. k Variation of capacitance of Ti3C2Tx/TiO2 composite at different relative humidity [209]. Copyright 2021, Royal Society of Chemistry. l Dynamic response-recovery curve of resistance for the pristine Ti3C2Tx and alkalized Ti3C2Tx under different RH [67]. m, n Resistance responses (R/R11%) of pristine Ti3C2Tx and alkalized Ti3C2Tx under different RH [67]. Copyright 2019, American Chemical Society