TiO₂ Hollow Nanofiber/Polyaniline Nanocomposites for Ammonia Detection at Room Temperature

Abstract Ammonia (NH₃) detection has gained considerable attention in agricultural and environmental monitoring, chemical and pharmaceutical processing, and disease diagnosis, which requires the development of sensors with high sensitivity. Herein, we propose a novel gas sensor based on nanocomposites of TiO₂ hollow nanofibers and polyaniline (PANI) for the sensitive detection of ammonia at room temperature. TiO₂ nanostructures in anatase phase were prepared by the combination of coaxial electrospinning and calcination treatment. The resulting material was mixed with PANI and deposited onto gold interdigitated electrodes (IDEs). The hybrid platforms exhibited superior sensing performance compared to the platform based on their individual phases, which is ascribed to a synergistic effect from p‐n heterojunction formation. Specifically, the platforms based on TiO₂/PANI nanocomposite showed a fast response towards NH₃ (e. g., 55 s at 10 ppm) at room temperature (25 °C). Additionally, the platform demonstrated the ability to detect NH₃ at low concentrations (10–30 ppm) and a detection mechanism was proposed to explain the results. Overall, these results show the promise of electrospun TiO₂ hollow nanofibers/PANI composites for the development of high‐performance room temperature ammonia sensors.