Prominent ethylene glycol sensing of sol–gel-derived ZnO and Cu-ZnO nanostructures

Within this work, pristine zinc oxide and copper-doped powders were prepared using a sol–gel technic. Important physical properties such as morphological, optical, and structural features of the samples have been studied. Different data including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller analysis (BET), UV–Vis spectrophotometry, and Fourier transform infrared spectroscopy (FTIR) were collected to investigate the physical features of the samples. In addition, the ethylene glycol vapor sensing capability of the prepared samples was investigated and compared with other vapors like as ethanol, methanol, acetone, isopropanol, and dimethylformamide. The results demonstrated that the samples have a very good selectivity to ethylene glycol (up to 50 times for ZnO and 13 times for Cu-ZnO 20%). The most important parameters of sensing namely operating temperature, real-time variation, sensitivity, and response/recovery times were also evaluated for pristine zinc oxide and copper-doped nanostructures. Specifically, the ZnO nanostructure sensor represented prominent sensitivity of about 37 and 139 towards ethylene glycol concentrations of 200 and 700 ppm, respectively.