Selective CO2 Detection at Room Temperature with Polyaniline/SnO2 Nanowire Composites

In this study, tin oxide (SnO2)/polyaniline (PANI) composite nanowires (NWs) with varying amounts of PANI were synthesized for carbon dioxide (CO2) gas sensing at room temperature (RT, 25 °C). SnO2 NWs were fabricated via the vapor–liquid–solid (VLS) method, followed by coating with PANI. CO2 sensing investigations revealed that the sensor with 186 μL PANI exhibited the highest response to CO2 at RT. Additionally, the optimized sensor demonstrated excellent selectivity for CO2, long-term stability, and reliable performance across different humidity levels. The enhanced sensing performance of the optimized sensor was attributed to the formation of SnO2-PANI heterojunctions and the optimal PANI concentration. This study underscores the potential of SnO2-PANI composites for CO2 detection at RT.