Enhanced NH3 detection by hollow polyaniline microspheres

To meet the growing demands for ammonia gas (NH 3 ) sensor, the development of high-performance sensing materials is essential. Herein, the polyaniline (PANI) pristine hollow microspheres (H-PANI) with high specific surface area were prepared through template removal approach, and then exhibited an enhancing NH 3 detection performance than PANI powders. Firstly, polyaniline core-shell hollow microspheres (PANI-TEMs) were prepared by in-situ oxidative polymerization of aniline onto the surface of thermally expandable microspheres (TEMs) template. Subsequently, H-PANI featuring a dense shell and a high specific surface area of 72.35 m 2 /g was obtained after the removal of the TEMs template. Based on the results of the morphology and the specific surface area of the hollow microspheres characterized by scanning electron microscopy (SEM) and N 2 adsorption-desorption technique, respectively, the preparation of PANI-TEMs and the removal process were investigated and optimized. Finally, when the obtained H-PANI was employed in NH 3 detection, according to the ratio of the changed resistance to the initial resistance, the sensitive response values of up to 144 for 3000 ppm NH 3 and 8 for 50 ppm NH 3 at room temperature were achieved, which could attribute to the increased specific surface area. This finding holds great potential for enhancing the sensitivity of ammonia detection materials.