Author(s): CONTI, P. P.; SANTOS, D. M. dos; GOLDTHORPE, I. A.; CORREA, D. S.

Summary: 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

Publication year: 2022

Types of publication: Journal article

Unit: Embrapa Instrumentation

Keywords: Chemiresistive sensors, Gas pollutants, Toxic gas