PANI/CoMoO₄ Nanocomposite Heterostructures for Detection of NH₃ at Room Temperature

The interface between two distinct materials in a heterojunction material plays a crucial role in gas sensors, as it facilitates the swift and effective transfer of charge carriers, resulting in enhanced response times. Nevertheless, the impact of heterogeneous interfaces on gas-sensing properties remains uncertain, impeding the advancement of semiconducting hybrids in gas-sensing applications. This study presents the synthesis of a PANI/CoMoO 4 p–p heterogeneous nanocomposite through in situ polymerization of highly active PANI onto CoMoO 4 . In the range of 0.05–50 ppm NH 3, PANI/CoMoO 4 exhibits a rapid response time of ∼5 s (50 ppm) and a low LOD of 50 ppb. PANI/CoMoO 4 has only 10% decrease in response to NH 3 during 40 days and demonstrates a high selectivity to NH 3 against H 2 S, CO, CH 4, and other interferents. The effective modification of PANI, as confirmed by density functional theory (DFT), enhances the adsorption efficiency of NH 3 molecules. Additionally, the p–p heterojunction interface between PANI and CoMoO 4 facilitates efficient electron transport. The findings of this study highlight the advantages of p–p heterojunctions in NH 3 detection, offering novel insights for the design and synthesis of high-performance gas-sensitive materials. Furthermore, effective utilization of the PANI/CoMoO 4 nanocomposite in portable gas sensors and inspection robots underscores their practicality.