Effect of Acid Treatment on the Single-walled Carbon Nanotube-based Gas Sensors

The effect of acid treatment on the single-walled carbon nanotube (SWNT)-based gas sensors was investigated and presented in this work. The experimental results revealed that the acid treatment did not only remove the catalytic particles from the SWNT bundles but also caused breakings of the SWNT bundles, leading to an enhancement in sensitivity and recovery of the sensors. After 60 min exposing to 50 ppm ammonia (NH₃) gas at room temperature in nitrogen ambience, the resistance of 4h-stirred SWNT-based sensor increased up to 80% compared to its initial value. The sensor recovery also was significantly improved owing to acid treatment. These findings opened a promising method for development of the SWNT-based gas sensors.