Ultrahigh sensitive and selective room-temperature carbon monoxide gas sensor based on polypyrrole/titanium dioxide nanocomposite

In this article, an ultrahigh sensitive and selective carbon monoxide (CO) gas sensor was developed and studied at room temperature utilizing the PPy/TiO2 nanocomposite. The gas sensors were fabricated through drop-casting the PPy/TiO2 nanocomposites on the surface of interdigitated electrodes. All the nanocomposites have been synthesized via a chemical oxidation method. Contrary to the pure PPy sensor, PPy/TiO2 sensor exhibited 4-fold enhanced sensitivity. Our sensor showed a superior response of order 93 at 270 ppm of carbon monoxide with high selectivity over the other interference gases. Additionally, our sensor exhibited a quick response time and a short recovery time of 36 s and 38 s, long-term stability, excellent repeatability, and satisfactory reproducibility. Accordingly, experimental findings proved that incorporating TiO2 into the PPy plays an influential role in enhancing the gas sensor performance. In this work, based on the outstanding CO sensing performance, the PPy/TiO2-based sensor might be considered a promising candidate for real-time gas sensor applications. [Display omitted] •The influence of the inclusion of TiO2 on the PPy sensing performance has been investigated.•An ultrahigh sensitive and selective CO sensor has been developed.•A gas sensing mechanism based on heterojunction was discussed.