Room temperature hydrogen and hydrocarbon sensors based on single nanowires of metal oxides

Hydrogen sensing characteristics of single nanowires of ZnO, TiO2 and WO2.72 have been investigated by contact mode atomic force microscopy. All these nanostructures are able to sense hydrogen, but the WO2.72 nanowire ( 40 nm diam) exhibits the highest sensitivity of 22 for 1000 ppm at 298 K. The WO2.72 nanowire is also found to be good at sensing aliphatic hydrocarbons in the form of liquefied petroleum gas with a sensitivity of 15 for 1000 ppm at room temperature. A WO2.72 nanowire with a diameter of 40 nm shows better sensing characteristics than a nanowire of 16 nm diameter.