Fabrication of a room temperature hydrogen sensor based on thin film of single-walled carbon nanotubes doped with palladium nanoparticles

摘要

A new sensor for the detection of hydrogen at parts per million (ppm) levels was fabricated by coating a thin film of palladium-doped activated single-walled carbon nanotube on the inner wall of a glass tube. The response of the sensor was based on the changes in the impedance of the sensor upon the adsorption of hydrogen molecules. The linear dynamic range of the sensor was from 1 to 50 ppm. The relative standard deviation of six replicate analyses of 5 ppm of H_2 was 2.1% and the limit of detection was 0.73 ppm for H_2 species. Humidity, methane and hydrogen sulphide did not have any serious effect on hydrogen recognition. Also, no interfering effect was observed when 20-fold excess (mass/mass) of carbon dioxide or carbon monoxide was present with hydrogen.