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

Abstract

In this article, an ultrahigh sensitive and selective carbon monoxide (CO) gas sensor was developed and studied at room temperature utilizing the PPy/TiO 2 nanocomposite. The gas sensors were fabricated through drop-casting the PPy/TiO 2 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/TiO 2 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 TiO 2 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/TiO 2- based sensor might be considered a promising candidate for real-time gas sensor applications. • The influence of the inclusion of TiO 2 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.