This study reports the synthesis
of CdS/WS2 composites
via a green and ultra-low-cost hydrothermal method. By controlling
the relative mass ratio between WS2 and CdS, an n–n
type CdS/WS2 heterostructure, with excellent NH3 gas-sensitive properties, was developed and investigated at room
temperature. Compared with pristine WS2 and CdS, the CdS/WS2-40%wt composite exhibited excellent selectivity of more than
4 orders of magnitude for sensing NH3, a very short recovery
time of 3 s, and ultrahigh selectivity at room temperature. The large
specific surface area of the CdS/WS2 composite increased
the active sites for the gas-sensitive reaction. Additionally, the
2D morphology of CdS/WS2 and the heterojunction formed
between WS2 and CdS contributed to the improved performance.
Anti-humidity interference tests showed that the CdS/WS2 sample remained stable under real-time monitoring of NH3 at different ambient humidity values. This study paves the way for
designing high-performance gas sensors operating at room temperature.