Selective and rapid detection of acetone using aluminum-doped zno-based sensors

We report the preparation and characterization of pure and doped ZnO nanoparticles with 1%, 3%, and 5% aluminum (AZO) using a sol-gel method followed by annealing at 400 degrees C for 2 h. The structural and morphological properties of the AZO nanoparticles were analyzed using X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) techniques, and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectrometry (EDS). Optical and specific area properties were investigated by photoluminescence (PL) and N-2 physisorption measurements. The results showed that pure and doped AZO nanoparticles crystallize under a hexagonal wurtzite structure and exhibit spherical shapes with nanometric dimensions. TEM and SEM images revealed that the pure and Al-doped ZnO were round nanoparticles with a size smaller that 100 nm. FTIR measurements were conducted to investigate the presence of Al-O stretching vibrations, which served as an indication of aluminum incorporation into the ZnO lattice. The results confirmed the successful integration of aluminum into the ZnO structure. Additionally, XPS measurements were performed to examine the elemental composition of the AZO samples. The presence of Zn 2p peaks in all AZO samples, along with the presence of Al 2p peaks in the Al-doped ZnO structures, provided further evidence for the successful incorporation of Al ions into the ZnO lattice. The PL spectra revealed the presence of various defects (oxygen vacancies, interstitials) in the structure of pure and doped ZnO. Moreover, we fabricated gas sensors by spray-coating the AZO nanoparticles on alumina substrates equipped with interdigitated gold electrodes. The sensors demonstrated linear responses to gas concentration in the range of 5 to 50 ppm, with high sensitivity and good reproducibility, particularly for A1ZO (1% Al-doped ZnO), which exhibited the highest response (similar to 12) at 300 degrees C under 10 ppm of acetone. Furthermore, A1ZO demonstrated excellent selectivity to acetone compared to other volatile organic compounds (VOCs) gases. Our findings highlight the potential of aluminum-doped ZnO nanoparticles as a promising material for enhancing the sensing properties of acetone gas sensors.

Automated summary

This study reports on the preparation and characterization of pure and doped ZnO nanoparticles and their potential as gas sensors. The AZO nanoparticles were prepared using a sol-gel method and annealed at 400 degrees C. The structural and morphological properties were analyzed using XRD, TEM, and SEM. Results showed successful aluminum incorporation into the ZnO lattice, and the nanoparticles exhibited a spherical shape with nanometric dimensions. Gas sensors fabricated using the AZO nanoparticles demonstrated linear responses to gas concentration, with high sensitivity and selectivity to acetone.