Self-assembly fabrication of titanium dioxide nanospheres-decorated tungsten diselenide hexagonal nanosheets for ethanol gas sensing application

This article demonstrates a high-performance ethanol gas sensor based on titanium dioxide/tungsten diselenide (TiO2/WSe2) nanocomposite. The TiO2 nanospheres (NSs) and WSe2 hexagonal nanosheets (HNs) were synthesized via an economical hydrothermal route. The TiO2/WSe2 nanofilm sensor was prepared on an epoxy substrate via self-assembly technology. The composition, morphology, microstructure of the prepared materials was characterized via XRD, XPS, SEM and TEM (HRTEM) measurements. The gas sensing property of TiO2/WSe2 nanofilm was fully researched at room temperature of 25 degrees C. The experimental results indicated that the TiO2/WSe2 sensing nanofilm achieved high response (42.8@100 ppm), extremely short response/recovery time (2 s/1 s@30 ppm), excellent selectivity and repeatability, stability and low detection limit for ethanol gas detection. The TiO2/WSe2 sensor is capable of identifying the exhaled alcohol vapor of a drunken man. The enhanced ethanol sensing performance of TiO2/WSe2 nanofilm was owing to the synergy effect and large adsorption surface area of binary nanostructures and p-n heterojunction between the TiO2 NSs and WSe2 HNs.