Acetone sensor based on Ni doped ZnO nanostructues: growth and sensing capability

This work presents the preparation of nanostructured zinc oxide (ZnO) thin films doped nickel (Ni) with the molar ratios [Ni]/[Zn] = 0.5; 1; 1.5; 2% M, using low cost spray pyrolysis method. Different characterization techniques were established, such as: X-ray diffraction that showed the hexagonal structure of the films confirmed by Raman spectroscopy. The grain size variations and the morphology according to doping levels were analyzed by scanning electron microscopy. Optical analysis was carried out, the films are transparent and the band gap energy varies opposing to Urbach energy. From experimental data, we observed that 2% Ni doped ZnO exhibited good characteristics and properties compared to pure ZnO and followed by the other samples. The gas testing confirmed the previous concepts, proving that 2% of nickel added to the basic solution enhanced; response/recovery time, response of the sensor and optimal working temperature. This sample demonstrated better selectivity to acetone detection with high response reaching 90, at 450 °C under 100 ppm.