Development of Methanol Sensors: Carbon Nanotubes Blended Hydroxyapatite Nano-Ceramics

摘要

The experimental study reports the performance of Carbon nanotubes (CNT) blended Hydroxyapatite (HAp) composites as a sensing material for the detection of methanol vapours. The main objective of the work is to improve the temperature dependent sensitivity of the sensor for lower methanol concentration. Moreover, the sensing ability of native HAp and CNT blended HAp thick films is studied in terms of operating temperature, response/recovery time, maximum detection limit. Thick films of the native and blended materials are fabricated via screen printing technique. The sensing parameters are studied using two probe electrical methods. The sensor substrate is made by means of doping of various concentrations of CNT in HAp. The sensing of methanol vapours is studied at a fixed concentration of 100 ppm. Native HAp substrate shows good sensitivity for methanol at room temperature; however its sensing performance is inferior to the CNT blended materials. The blended composites exhibit impressive sensing ability compared with native HAp in terms of sensitivity, response/recovery time and maximum uptake the limit. The sensing mechanism for methanol detection, the role of HAp as a parent material and CNT as an additive, is explained using a suitable sensing mechanism.