Silver Growth on Tungsten Oxide Nanowires for Nitrogen Dioxide Sensing at Low Temperature †

International audienceGas sensors produced and working at low temperatures are particularly interesting for their compatibility with temperature sensitive substrates such as flexible ones or for their use in specific environments. In this work, we present the chemical synthesis of silver nano-islands grown on ultrathin tungsten oxide nanowires (Ag/WO3 NWs) in order to obtain sensing materials for nitrogen dioxide (NO2) detection at temperatures below 150 °C. We compare the efficiencies of NO2 gas sensing, for WO3 NWs both before and after the silver growth, by drop-casting the nanomaterials from colloidal solutions onto substrates. Interestingly, the working temperature is reduced down to 130 °C even for NO2 concentrations as low as 0.2 ppm, with a clear improvement in sensitivity in the case of the Ag/WO3 NWs. Additionally, continuous UV irradiation reduced greatly the recovery time

Ammonia Detection at Low Temperature by Tungsten Oxide Nanowires

International audienceAmmonia detection at low temperatures below 150 °C is attractive to be well suited for flexible substrates in terms of thermal strain and to specific environment not allowing high temperature such as explosive one. In commercial gas sensors, tungsten trioxide is the mostly used semiconducting metal oxide after tin dioxide. We report herein the efficiency of tungsten trioxide nanowires deposited on rigid substrate by drop coating from colloidal solution. This study provides an interesting approach to fabricate ammonia sensors on conformable substrate with significant properties for applications in environmental monitoring devices