Highly sensitive and fast response Love wave mode humidity sensor based on MoS2@Ti3C2Tx hierarchical structure

Humidity sensing is crucial for food production, environmental monitoring, microelectronic manufacture, and common living conditions. Thus, there is a high demand for development of high-performance humidity sensors with good stability, high precision and fast responses. In this study, Love wave mode humidity sensors were prepared using quartz-based SAW devices coated with composite sensing layers of accordion-like Ti 3 C 2 T x , MoS 2 nanoflowers and MoS 2 @Ti 3 C 2 T x hierarchical structure, respectively. The hydrophilic Ti 3 C 2 T x was used to provide abundant surface functional groups for adsorption of water molecules, and the hydrophobic MoS 2 enabled rapid adsorption and desorption of water molecules from the surface of MoS 2 @Ti 3 C 2 T x . The MoS 2 @Ti 3 C 2 T x coated Love wave humidity sensor presented an ultra-high sensitivity of 0.67 kHz/% RH in the wide humidity range from 11.3% RH to 97.3% RH, mainly attributed to the hierarchical structure of MoS 2 @Ti 3 C 2 T x with large specific surface areas, abundant adsorption sites and superhydrophilicity. Meanwhile, this Love wave humidity sensor showed fast response/recovery rates, great repeatability and long-term stability, indicating its great prospects in humidity detection applications.