H2S sensors based on tungsten oxide nanostructures

Nanoparticles and nanoplatelets of WO3 and nanowires of WO2.72 have been investigated for their H2S-sensing characteristics over the 1-1000ppm concentration range at 40-250 degrees C. The nanoparticles and nanoplatelets of WO3 exhibit response values of 757 and 1852, respectively to 1000ppm H2S at 250 degrees C, respectively, compared to the response of 3313 of the nanowires of WO2.72. Interestingly, the response of the nanowires is satisfactory (121) to 10 ppm H2S at 250 degrees C, while a large response (240) is observed to 1000 ppm H2S even at 40 degrees C. The WO2.72 nanowires emerge as a good candidate for H2S sensors, with little effect of humidity up to 60% relative humidity as well as satisfactory response and recovery times. (C) 2007 Elsevier B.V. All rights reserved.