Development of highly sensitive and selective ethanol sensor based on lance-shaped CuO nanostructures

Highlights: • Facile synthesis of CuO nanostructures • Fabrication of highly sensitive and selective ethanol gas sensor • High selectivity of the developed sensing device against H₂ and CO gases Herein, we report the successful synthesis and characterization of lance-shaped CuO nanostructures prepared by a simple and facile hydrothermal technique. The prepared nanostructures were examined by several techniques which revealed that the lance-shaped nanostructures are well-crystalline, grown in very high density and possessing monoclinic crystal structure. In order to develop a nano-device using synthesized nanomaterial, the prepared powder was coated on the alumina substrate with suitable electrodes and the fabricated sensor device was tested for ethanol gas. Interestingly, the gas response (resistance ratio) and response times for the fabricated devices were 9.1 and 127 s, respectively for 100 ppm of C₂H₅OH at 300 °C. Further, the selectivity of the developed sensing device was tested against H₂ and CO gases and interestingly, it was observed that the fabricated sensor exhibited excellent selectivity towards ethanol gas.