Carbon dioxide sensing using a PEI-Cr₂O₃-rGO nanocomposite sensor with patterned copper clad as a substrate

ABSTRACT

The focus of this work is on carbon dioxide sensing using a nanocomposite sensor composed of PEI, Cr₂O₃, and rGO, with a patterned copper-clad substrate. Study explores how sensors with varying weight percentages of Cr₂O₃ and rGO in PEI perform in terms of sensitivity when exposed to carbon dioxide gas. Furthermore, the study probed into exploring the correlation between the fluctuations in electrical resistance of the sensors and the levels of CO₂ gas concentration. This examination delves into the sensitivity, repeatability, response time, and recovery time of the sensors. At 1000 ppm of CO₂, the sensor with 0.25 wt% of Cr₂O₃-rGO in PEI demonstrated the lowest sensitivity percentage of 1.71, while the highest sensitivity of 2.13 was achieved by the sensor with 1.0 wt% of Cr₂O₃-rGO in PEI. The repeatability of the sensors containing 0.25, 0.50, 0.75, and 1.00 wt% of Cr₂O₃-rGO in PEI was found to be comparable at 8 minutes. However, the repeatability of the sensor with 1.00 wt% of Cr₂O₃-rGO in PEI was especially noteworthy. A PEI nanocomposite with 0.25 wt% Cr₂O₃-rGO demonstrated the quickest response time of 33 seconds and recovery time of 36 seconds compared to the other sensors. The sensing mechanism involves the physical absorption of CO₂, the effective interactions of the amino groups with CO₂ to form carbamates, and the electrical response changes of the PEI-Cr₂O₃-rGO nanocomposite at room temperature. This mechanism provides a reliable and efficient means of sensing CO₂ gas for various applications at equal to or less than 1000 ppm.

GRAPHICAL ABSTRACT

KEYWORDS:

• Carbon dioxide sensing
• interdigitated electrode
• polyethylenimine
• rGO
• Cr₂O₃ and copper clad

Disclosure statement

No potential conflict of interest was reported by the author(s).