Interfacial charge transfer and p–p heterojunction formation in MoS2@SWCNT mixed-dimensional architectures for humidity transduction

Emerging nanotechnologies have drawn tremendous focus on hybrid nanostructured materials as they exhibit unique and multifunctional properties. One class of particularly promising advanced materials is 2D/1D nanostructures. In this study, hexagonal-shaped MoS 2 nanoflakes are grown directly on single-walled carbon nanotubes (SWCNT) using a sequential chemical vapor deposition technique (CVD) and molecular beam epitaxy (MBE). Raman and REELS measurements provide clear evidence of strong interfacial electronic coupling and p-type doping of the SWCNT network induced by MoS 2 . Temperature and humidity exposure tests confirm that the hybrid materials exhibit a higher concentration of hole carriers, indicating p-doping of SWCNT by the MoS 2 nanoflakes. A qualitative sensing mechanism is proposed, highlighting the interplay between interfacial charge transfer and water adsorption through ionic pathways. The hybrid materials show rapid response and recovery times, along with minimal hysteresis behavior. These findings pave the way for the development of efficient and reliable MoS 2 @SWCNT-based hybrid materials transducers for gas sensing applications, offering high selectivity based on gas-edge interactions.