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We have characterized the electrical transport properties of Au/WO 3 nanowire/Au devices in ambient air and gaseous H 2 S to investigate the adsorption kinetics of H 2 S molecules on the surface of WO 3 nanowire at room temperature. The WO 3 nanowire devices exhibit increasing linear conductance and electrical hysteresis in H 2 S. Furthermore, the contact type between Au electrode and WO 3 nanowire can be converted from original ohmic/Schottky to Schottky/ohmic after being exposed to H 2 S. These results suggest that adsorbed H 2 S molecules are oxidized by holes to form hydrogen ions and S atoms, which will result in formation of hydrogen tungsten bronze and desorption of previously chemically adsorbed H 2 O molecules. Adsorbed H 2 S molecules can also oxidize previously adsorbed and ionized oxygen, which will release the electrons from the ionized oxygen and then weaken upward band bending at the surface of WO 3 nanowire. V C 2014 AIP Publishing LLC. [http://dx.