A morphological control of tungsten oxide nanowires by thermal evaporation method for sub-ppm NO2 gas sensor application

作者：Nguyen Van Hieu^*; Hoang Van Vuong; Nguyen Van Duy; Nguyen Duc Hoa

来源：Sensors and Actuators B: Chemical , 2012, 171: 760-768.

DOI：10.1016/j.snb.2012.05.069

• Tungsten oxide
• Nanowires
• Gas sensor
• NO2

Controlling the proper geometrical morphology of metal oxide nanowires (NWs) with large surface areas is important for enhancement of gas-sensing performance through the improvement of sensing sites. In this study, we synthesized geometrically controllable tungsten oxide NWs for detection of NO2 at sub-ppm concentrations. Tungsten oxide NWs were grown through the thermal evaporation method using WO3 powders and W foils as precursor and substrates, respectively. Effects of growth conditions on the morphologies and gas-sensing properties of synthesized NWs were investigated. Results revealed that the as-obtained NWs possessed a cross-section of polygonal shapes, and their diameters increased as the growth temperature increased from 950 degrees C to 1000 degrees C. However. the NWs formed bundles and generated porous structures as the growth temperature increased up to 1050 degrees C. The comparative NO2 gas-sensing properties of tungsten oxide NWs synthesized at different growth temperatures indicated that the NWs synthesized at 1050 degrees C exhibited relatively good NO2 sensing performance at the sub-ppm level because of the formation of porous NW structures. This phenomenon suggested that porous tungsten oxide NWs are effective for highly sensitive NO2 gas sensor applications.

• 出版日期2012-9
• 单位华中科技大学