Composition of CNT and WO3 nanoplate: synthesis and NH3 gas sensing characteristics at low temperature

Abstract

WO₃ nanoplate synthesized by acid precipitation method was composited with commercial carbon nanotube with different weight percents (0.5, 1.0, and 1.5 wt% of CNT). The ammonia gas sensing characteristics of composite materials at low temperature (50°C) were investigated and compared with that of pristine materials (WO₃ nanoplate, commercial carbon nanotube). The results showed that the composition enhanced the gas sensing properties in comparison with the pristine carbon nanotube-based sensor and more stable than pristine WO₃ nanoplate-based sensor. The response of gas sensors to 30 ppm of ammonia got the highest value of 45% in 0.5 wt%-CNT sensor – enhanced 100 times in comparison with carbon nanotube-based sensor. The calculated limit of detection of 0.5 wt%CNT/WO₃ sensor was at sub-trace-level of 3 ppb. This enhancement shows the high applicability of composite materials in gas sensor working at room temperature.