Fig. 5. (a) Gas response of the gas sensors toward 5 ppm H2S under different operating temperatures; (b) response–recover time curve of the WO3 and CeO2/WO3-2 sensor to 2.5 ppm H2S gas at 115 °C; (c) dynamic response curves of the WO3 and CeO2/WO3 sensors to 0.5–5 ppm H2S gas at 115 °C; (d) the selectivity to 5 ppm H2S and other volatile gases for WO3 sensor and CeO2/WO3 sensors at 115 °C.
