Tungsten trioxide nanoparticles decorated tungsten disulfide nanoheterojunction for highly sensitive ethanol gas sensing application

A tungsten disulfide/tungsten trioxide (WS2/WO3) based ethanol sensor was fabricated by layer-by-layer self-assembly technique, which was deposited on a substrate with interdigital electrodes. The composition, morphology and structure of the WS2/WO3 nanocomposite were analyzed using a variety of characterization methods, including XRD, SEM, TEM, XPS and EDS. The gas sensing properties of the WS2/WO3 sensor were studied in different concentrations of ethanol gas at 25 °C. The WS2/WO3 film sensor exhibited low detection limit, excellent selectivity, stable repeatability, outstanding stability, and rapid response-recovery features. The sensing mechanism of the sensor is attributed to the unique charge transfer properties of the WS2/WO3 heterojunction and the synergistic effects of the combination of WS2 and WO3. The WS2/WO3 sensor was significantly verified to be a qualified candidate for the detection of ppb-level ethanol gas.