Effects of Doping on the Gas-Sensing Response of Ga-Doped ZnO Nanoparticles

This research depicted a modified sol–gel method to synthesize nanoparticles of gallium-doped zinc oxide (ZnO) with the intention of creating gas sensor devices that had enhanced sensing layers. Various techniques were employed to characterize these nanoparticles, including X-ray diffraction (XRD) for structural analysis, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) for morphological examination. The XRD results confirmed the good crystallinity of the samples in the hexagonal system. Both SEM and TEM images revealed that the nanoparticles had a size of approximately 30 nm, and the incorporation of gallium as a dopant reduced their size. Following that, gas sensors based on gallium-doped ZnO were tested at temperatures ranging from 250 to 450 °C. According to the experimental results, ZnO doped with 3% gallium exhibited heightened response when exposed to 500 ppm ethanol at its operating temperature of 450 °C. In comparison to methanol gas, the response and recovery times were shorter, and the selectivity was greater. These outcomes have significant implications for controlling air quality, particularly in industries that utilize organic solvents.