Performance of interdigitated capacitive-type CO2 sensor based on polypyrrole/copper phthalocyanine nanocomposite

In this study, we present the performance of interdigitated capacitive-type gas sensor devices based on polypyrrole/copper phthalocyanine (PPy/CuPc) nanocomposite, for sensing of CO2 gas at room temperature. In this framework, the PPy/CuPc nanocomposites have been synthesized by a simple in situ chemical oxidation polymerization in the presence and absence of cationic surfactant. The synthesized samples have been analyzed using field emission scanning electron microscopy and Fourier-transform infrared spectroscopy in order to study surface morphology and nanocomposite formation. The interaction of developed gas sensors with CO2 was registered by the change in capacitance. Under exposure to CO2 gas in the range of 0.1-1% at room temperature, all fabricated sensor show reversible, reproducible, and linear response. Particularly, the PPy/CuPc nanocomposite containing highly interconnected network of PPy nanofibers exhibits higher response and sensitivity toward CO2 gas compared to particle-like PPy/CuPc nanocomposite and pure PPy. The long-term stability of gas sensor devices have also been examined in particular concentration of CO2 gas within 30 days by monitoring the change in capacitance response. The sensing performance of the capacitive-type gas sensor based on the PPy/CuPc nanocomposite may be of interest for CO2 detection in future studies.