Hierarchically Structured V2O5/PANI Heterostructures for Room-Temperature Ammonia Sensing.

Ammonia, a toxic and volatile pollutant commonly found in chemical industrial environments, requires reliable real-time detection to ensure industrial safety and effective environmental monitoring. Conventional gas sensors typically operate at elevated temperatures, resulting in high power consumption. Moreover, pure metal oxides and conductive polymers often suffer from significant aggregation and exhibit suboptimal sensing performance under ambient conditions, limiting their practical applications. In this study, hierarchical porous V2O5/PANI composites were synthesized via a straightforward one-step coprecipitation method combined with in situ polymerization. The interlaced architecture of polyaniline (PANI) and vanadium pentoxide (V2O5) effectively reduces structural aggregation and increases the availability of surface active sites. Furthermore, the synergistic interaction at the bi-phase interface significantly enhances charge carrier transport, leading to improved ammonia-sensing capabilities at room temperature. Notably, the composite containing 20% V2O5 demonstrated superior response, selectivity, and reproducibility toward 10 ppm NH3. Due to its simple fabrication process and room-temperature operation without external heating, the developed V2O5/PANI composite sensor holds significant potential for practical applications in low-concentration ammonia detection under ambient conditions.