Authors: B-W Chang, S-J Ding, R.L.C. Chen
Affilation: Hungkuang University, Taiwan
Pages: 72 - 75
Keywords: hydrogen sulfide, tin dioxide, gold nanoparticle
A highly sensitive and selective H2S gas sensor has been developed by deposited a SnO2 thin film on an alumina substrate with a spin-coated method. This SnO2 sensing film was be made by a sol-gel method, and for getting a good sensitivity and selectivity we doping a mixture composite by Au nanoparticles with SnO2. The photography of self-developed sensor is shown in Fig. 1. In charactering of this sensing film, we used X-ray diffraction to analyze the composition of SnO2/Au nanocomposites, and used the SEM and TEM images for observing the morphology and the particle size, the data are shown in Fig. 2(a)(b). The results of experiments showed that for hydrogen sulfide detection, there have a good linear response in SnO2+1Au composites, the detection range was from 0.2 ppm to 0.5 ppm at room temperature, and the selectivity the sensor shown that in Au doping composites have a good selectivity to H2S against SO2, NH3 CO2 O2 and alcohol. The sensor had speedy response kinetics to H2S, the 90% response time to 0.2 ppm H2S was 60 s, and the recovery time was 30 s. We also studied the effect of humidity (50%, 70% and 80% RH) to H2S detection. The result showed the influence of humidity that was needed to be concerned in practical use.