Selectivity and sensitivity of Pd-loaded and Fe-doped SnO2 sensor for CO detection

Pd-loaded and Fe-doped SnO2 was prepared by sol–gel method. The composition, morphology and electrochemical property of the material were characterized by XRD, SEM and electrochemical workstation respectively. The results showed that Pd-loaded and Fe-doped SnO2 had the same crystal structure as pure SnO2, and the crystalline degree was reduced with the increasing of doping amounts of Fe. In addition, the sample had a higher response value of CO when modifying with Fe/Pd. When adding amounts were 10 mol% Fe and 0.2 mol% Pd, the composite had the highest sensitivity and selectivity to CO in range of 200–3000 ppm at 350 °C. The response value of the composite material to 2000 ppm CO was raised 13 times than that of pure SnO2. The results also showed that Pd-loaded and Fe-doped SnO2 had drastically enhanced the selectivity of CO against H2 than pure SnO2.