Synthesis and characterization of highly sensitive ammonia sensor based on polyaniline/bismuth doped zinc oxide composites

Abstract Highly efficient gas sensors fabrication having low detection limits have been one of key research area due to the industrial, environmental and other technological applications. In this study, polyaniline/bismuth doped zinc oxide (PANI/Bi‐ZnO) was prepared via inverse emulsion polymerization and it was coated over a substrate with staggered electrodes to create a highly efficient ammonia (NH 3 ) sensor. The UV/Vis investigation, fourier transformed infrared (FTIR), raman spectral analysis, and scanning electron microscopy (SEM) were used to describe the structure and morphology of prepared samples. At room temperature, the PANI/Bi‐ZnO sensor's sensitivity to various NH 3 gas concentrations ranging from 20 to 100 ppm was examined. According to the experimental findings, the PANI/Bi‐ZnO film exhibits outstanding performance of response and selectivity. The response at 20 ppm NH 3 was as high as ⁓100%. The response and recovery time was also calculated at 20 ppm and was 11/15 s. The contact between p‐n heterojunctions in the composite is responsible for the exceptional sensitivity of PANI/Bi‐ZnO towards NH 3 sensing. Highlights Synthesis of Bi doped ZnO composites with PANI at room temperature Fabrication of highly sensitive and efficient resistive type ammonia sensor Selective and robust detection of ammonia by the fabricated sensor High sensitivity with low limit of detection offered by the sensor Response of the fabricated sensor at 20 ppm NH 3 was as high as ⁓100%