Sensing properties and mechanism of gas sensor for H2S and NO2 based on [Cu5(bipyO2)6Cl8]Cl2

In this work, the thick film sensors were produced from [Cu5(bipyO2)6Cl8]Cl2 and their gas sensing properties were studied. It was found that the sensors not only had high responses to above 0.013% NO2 and above 0.017% H2S at room temperature, but also had favorable gas distinguishability. The response and recovery time were about 8 s and 10 s to H2S, respectively, but they were about 8 s and 12 s to NO2. The sensor also had good consistency and reproducibility. This is the first report of room temperature sensing of a metal complex to NO2 and H2S. It was demonstrated by theoretic analysis that the sensing mechanism was explained by using a double energy valley model. The calculated values and experimental data were in good agreement with each other.