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/CoMoO4 p–p heterogeneous nanocomposite through in situ polymerization of highly active PANI onto CoMoO4. In the range of 0.05–50 ppm NH3, PANI/CoMoO4 exhibits a rapid response time of ∼5 s (50 ppm) and a low LOD of 50 ppb. PANI/CoMoO4 has only 10% decrease in response to NH3 during 40 days and demonstrates a high selectivity to NH3 against H2S, CO, CH4, and other interferents. The effective modification of PANI, as confirmed by density functional theory (DFT), enhances the adsorption efficiency of NH3 molecules. Additionally, the p–p heterojunction interface between PANI and CoMoO4 facilitates efficient electron transport. The findings of this study highlight the advantages of p–p heterojunctions in NH3 detection, offering novel insights for the design and synthesis of high-performance gas-sensitive materials. Furthermore, effective utilization of the PANI/CoMoO4 nanocomposite in portable gas sensors and inspection robots underscores their practicality.