Highly sensitive Ti3C2Tx MXenes-RGO humidity sensor for human non-contact respiratory monitoring

In this study, a highly sensitive and stable Ti3C2Tx MXenes-RGO humidity sensor was developed for real-time respiratory monitoring. Ti3C2Tx-RGO composite material increases the interlayer spacing of RGO, further expanding the channels for water molecule transport. Introduction of Ti3C2Tx promotes the generation of more-O,-OH,-F groups on the composite material surface, which can serve as adsorption sites for water molecules to improve response, and they form weak physical adsorption with water molecules, shortening the response and recovery time of the sensor. Ti3C2Tx-RGO composite material increases the interlayer spacing of RGO, further expanding the channels for water molecule transport. Density functional theory (DFT) calculation results indicate that Ti3C2Tx surface-F has higher adsorption energy for water molecules, which is beneficial for enhancing the sensitivity of the humidity sensor. Ti3C2Tx-RGO humidity sensor exhibits high sensitivity (22,117), low humidity hysteresis (1%), relatively short response/recovery time (7/16 s), and good stability and repeatability in the range of 11%-95% RH. The sensor can also monitor changes in respiratory intensity and frequency, achieving real-time analysis of respiratory patterns, making it demonstrate strong application potential in non-contact human respiratory detection. This study provides new research ideas and methods for preparing high-performance humidity sensors.

Automated summary

A highly sensitive and stable Ti3C2Tx MXenes-RGO humidity sensor was developed for real-time respiratory monitoring. The sensor exhibits high sensitivity, low humidity hysteresis, short response/recovery time, and good stability and repeatability.