H2S sensing properties of WO3 nanowires sheathed with ZnO by atomic layer deposition

초록

WO3-core/ZnO-shell one-dimensional nanostructures were synthesized by catalyst-free thermal evaporation of WO3 powders followed by atomic layer deposition of ZnO. Scanning electron microscopy observations revealed that the nanostructures were of a rod-like morphology with diameters in a range from a few tens to a few hundreds of nanometers, lengths up to a few tens of micrometers, and a shell layer thickness in a range of ~15 nm. The gas sensors fabricated from multiple networked WO3-core/ZnO-shell nanowires showed significantly enhanced electrical response to H2S gas at 300 oC. In addition, the mechanism for the enhancement of the H2S gas sensing properties of the WO3 nanowires by ZnO sheathing is discussed.