Enhancing room temperature ethanol sensing using electrospun Ag-doped SnO₂–ZnO nanofibers

The present study reports room temperature ethanol sensing with improvement in response and recovery times using Ag-doped SnO₂–ZnO composite nanofibers. A comparative study of nanofibers of solo SnO₂, SnO₂–ZnO nanocomposite and Ag-doped SnO₂–ZnO nanocomposite is presented. Nanofibers of tin oxide and zinc oxide are deposited on low-cost aluminum electrodes using electrospinning technique to analyze their gas sensing characteristics towards volatile organic compounds, especially ethanol. The effect of Ag doping on nanocomposite of SnO₂ and ZnO has been studied and analyzed in terms of various gas sensing parameters viz. % response, response/recovery time, and selectivity. Ag-doped SnO₂–ZnO nanofibers have shown excellent response towards low concentration of ethanol (38.78% for 0.5 ppm) at room temperature (RT) with quick response and recovery times. X-ray diffraction, X-ray photoelectron spectroscopy, I–V characterization, energy dispersive X-ray spectroscopy, and scanning electron microscopy characterizations are done to show the crystallite size, valence state, electrical properties, elemental analysis, and surface morphology of the deposited nanofibers, respectively. The effect of doping on the surface characteristics is also analyzed by calculating and comparing the crystallite size of doped and undoped nanofibers. Moreover, the use of sol–gel process route, electrospinning deposition technique, and aluminum as the electrode and glass substrate make the fabrication of the sensor very cost effective.