Effect of Platinum Doping on the Morphology and Sensing Performance for CuO-Based Gas Sensor

Pristine and Pt-doped CuO nano-flowers were synthesized by a simple water bath heating method in this paper. Highly sensitive hydrogen sulfide (H2S) gas sensors based on Pt-doped CuO nano-flowers were fabricated. Scanning electron microscopy, X-ray diffraction, inductively coupled plasma atomic emission spectrometry, and energy dispersive X-ray spectroscopy were used to examine the characteristics and morphology of materials. The sensing performances of sensors with different concentrations of Pt dopants were evaluated at different operating temperatures. The results indicated that the CuO sensor doped with 1.25 wt % Pt exhibited the highest response (R-g/R-a, where R-g is the resistance in gas, and R-a is the resistance in air) of 135.1 to 10 ppm H2S at 40 degrees C, which was 13.1 times higher than the response of a pure CuO sensor. Pt doping also plays an important role for the enhancement of H2S selectivity against C2H5OH, NH3, H-2, CH3COCH3, and NO2.