Room temperature H2S sensing properties and mechanism of CeO2–SnO2 sol–gel thin films

Using non-alkoxide SnCl2·2H2O, Ce(NH4)2(NO3)6 as precursors, room temperature H2S gas sensitive CeO2–SnO2 thin films have been obtained. In this paper, the synthesis process of CeO2–SnO2 thin films has been introduced; the gas sensing properties of the CeO2–SnO2 thin films were investigated and compared with those of SnO2 and ZrO2–SnO2 thin films. The experiments illustrate that CeO2–SnO2 thin film has quite a quick response and recovery behavior, high selectivity, and has better sensitivity than that of ZrO2–SnO2 thin film toward low concentration of H2S at room temperature. The sensing mechanism of CeO2–SnO2 thin films toward H2S at room temperature has also been discussed in this paper.