High performance chemiresistive carbon-nanotube ammonia gas sensor surface modified by tantalum oxide (Ta₂O₅) metal nanoparticles

We have studied the response behaviour of bare and embellished Multiwalled Carbon Nanotubes (MWCNTs) in gas sensing, as well as their gas sensing properties have been thoroughly analysed. Pure tantalum oxide (Ta₂O₅) metal nanoparticles are deposited onto carbon nanotubes using the RF-sputtering technique. In terms of sensing response, the response in a decorated sensor was 565%, much greater than the pristine CNT response of 97%. The entire process was tested with an ammonia gas concentration of 10 ppm at room temperature. We’ve seen fast response time in pristine MWCNTs (1–15 s) and in embellished MWCNTs it was (1–4 s). The sensitivity value was 50% for pristine, while for the (10 min) decorated MWCNT sensor, it was 79%. According to the observed sensor response graph, a recovery of 75–85% had been achieved. The recovery time of pristine and decorated were seen as (1–14 s) and (1–6 s) respectively.