Enhanced gas sensing characteristics of metal doped WS2 nanoflowers

Herein, we demonstrate gas sensing characteristics of metal-decorated WS2 towards ammonia (NH3) gas detection at moderate temperature. Chemiresistive sensors are fabricated using a combination of chemical vapor deposition method with sputter deposition technique. WO3 nanowires grown via aerosol assisted chemical vapor deposition technique are sulfurized to form tungsten disulfide nanoflowers. The as grown nanoflowers are then decorated with metal nanoparticles of gold, silver and palladium using the sputtering technique at different deposition time and temperatures. The morphological and structural characteristics were studied using FE-SEM and Raman spectroscopy. The performance of the three fabricated sensors is compared towards NH3 gas detection at room and elevated temperatures. Results show that the synthesized material (WS2/Pd, WS2/Au, WS2/Ag) behaves as a p-type semiconductor towards NH3 gas. Also, the results of NH3 gas sensing characteristics demonstrated the promising effects of palladium decoration for the enhanced response in low-power consumption. Moreover, the room-temperature operation of the three sensors is discussed. Hence, this study demonstrates the realization of a high-performance NH3 gas sensor using a facile route along with low power consumption.