Ethylene glycol-sensing properties of hydrothermally grown feather-like ZnO nanopowder with abundant oxygen vacancies

The hydrothermal method was used to prepare feather-like ZnO nanopowder for sensing application. The morphological and structural properties have been investigated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The abundance of oxygen vacancy was directly confirmed through the XPS and PL data and was implicitly approved by the resistance variations as a function of the temperature. The gas sensing features were examined toward methanol, isopropanol, dimethylformamide, acetone, ethanol, and ethylene glycol vapors. The results showed that this sample has a very good selectivity to ethylene glycol (about 4-7 times more than other vapors). The best operating temperature, dynamic response, sensitivity, response/recovery times, and the detection limit of the sample were studied. The effect of the humidity on the performance of the sensor was also investigated.