Fabrication and gas sensing properties of Au-loaded SnO2 composite nanoparticles for low concentration hydrogen

Pure and Au-loaded SnO2 are synthesized by the method of sol-gel. XRD, SEM, XPS and electrochemical workstation are used to characterize the crystal structure, surface morphology, chemical composition and electrochemical property of the material, respectively. The effect of operating temperature and Au loading on n value is studied. It is shown that the response time of Au-loaded SnO2 sensor to 2000 ppm H2 is 43 s at 200 °C, which is much shorter than that of pure SnO2 sensor. It is found that the Au-loaded SnO2 sensor can detect H2 down to 1 ppm. Meanwhile, the Au-loaded SnO2 selectivity to H2 against CO is given. In conclusion, the Au-loaded SnO2 sensor is a good candidate for practical H2 sensors.