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Propane sensor pellets based on nanopowders Cu-doped ZnO

Cu-doped zinc oxide (ZnO:Cu) powders were synthesized by the co-precipitation technique, by using different doping concentrations (1, 3 and, 5 at %). The structural properties of the powders were analyzed by X-ray diffraction (XRD), the morphology was investigated by scanning electron microscopy (SEM). Cu-doped ZnO and ZnO undoped pellets were manufactured with a pressing machine, using a pressure of 5 tons for 4 min. The sensing properties of these pellets were measured at different propane (C3H8) concentrations and operation temperatures. A hexagonal wurtzite phase was confirmed by XRD characterization. Powders with a crystallite sizes of around 25–27 nm were obtained. Contrary to the expected, ZnO-U pellets registered a higher sensitivity as compared with those doped.