High-performance H2S gas sensor utilizing MXene/MoS2 heterostructure synthesized via the Langmuir–Blodgett technique and chemical vapor deposition

Abstract

In this study, we developed an H₂S gas sensor based on a MXene/MoS₂ heterostructure, using the Langmuir–Blodgett (LB) technique and chemical vapor deposition (CVD). Ti₃C₂T_x MXene nanosheets were uniformly transferred onto SiO₂/Si substrates via the LB technique, achieving near-complete coverage. Subsequently, flower-like MoS₂ was grown on the MXene-coated substrate through CVD, with vertical growth observed on the MXene layers. Our hybrid sensors exhibited a significant enhancement in gas response, with the MXene/MoS₂ heterostructure showing a response of 0.5 to H₂S – approximately five times greater than that of pristine MXene. This improvement is attributed to the formation of a heterojunction, which increases electron mobility and reduces the depletion layer, enabling more efficient gas detection. Furthermore, the sensor demonstrated excellent selectivity for H₂S over other gases, including H₂, NO₂, NH₃, NO, and VOCs. The combination of the LB technique and CVD not only enhances gas sensor performance but also offers a promising strategy for synthesizing materials for various electrochemical applications.