Improved carbon dioxide gas sensing features of zinc oxide nanorods assisted by an organic filler for dynamic situations

Zinc oxide (ZnO) nanorods prepared by a simple hydrothermal method. The characterization of the sample revealed the formation of the ZnO nanorods with hexagonal wurtzite structure. The CO2 sensing properties of the resistive-type sensor based on ZnO nanorods assisted by polyvinyl alcohol (ZFS) investigated as a function of gas concentration and relative humidity (RH) at room temperature. The response and response time of the ZFS reduced with increasing RH from 30 to 90% at various gas levels. The sensor showed the highest response of 120.3% at 0.3 vol% CO2 and 30% RH, while it exhibited a proper response of 81% at 90% RH and 0.037 vol% CO2. Moreover, the lowest response time (recovery time) of 51.3 s (34 s) at 0.3 (0.037) vol% CO2 and 90% RH was obtained. We found that our hand-made sensor has superior response features at dynamic conditions, a good CO2 selectivity, and long-term stability. Finally, the probable CO2 sensing mechanism of the ZFS was discussed in detail. [GRAPHICS] .