Ag-doped ZnO nanoellipsoids based highly sensitive gas sensor

Herein, we report the facile synthesis, characterization and methanol gas sensing application of Ag-doped ZnO nanoellipsoids (NEs). The NEs were synthesized by a simple hydrothermal method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) attached with energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR), UV-visible and Raman-scattering spectroscopy. The detailed characterizations confirmed the high-density growth, well-crystallinity and wurtzite hexagonal phase of the synthesized Ag-doped ZnO NEs. The morphological studies revealed the average width at the center and length of Ag-doped ZnO NEs are similar to 110 nm and similar to 250 nm, respectively. A theoretical band gap energy of similar to 3.26 eV was observed for NEs from the UV-Vis. spectroscopy. Further, the NEs were used as potential scaffold for the fabrication of methanol (CH3OH) gas sensor. The performance of the fabricated sensors was evaluated at 270, 320, and 370 degrees C and it was observed that the sensors exhibited best sensing performance at 370 degrees C. At optimized sensing temperature (370 degrees C), the fabricated sensor unveiled a gas response of 15.831 for 200 ppm of methanol gas. The response (tau(res)) and recovery (tau(res)) times measured from the voltage response transient of 100 ppm methanol gas at an optimized temperature of 370 degrees C were 11 s and 18 s, respectively.