fig5

Figure 5. Response and recovery curve towards 100 ppm NO₂ at RT for (A) PANI and (B) CuO-PANI-2; (C) Dynamic NO₂ sensing response-recovery curve to 100 ppm NO₂ at RT of CuO-PANI-1, CuO-PANI-2 and CuO-PANI-3; (D) The response and (E) fitting function curves for CuO-PANI-2 at RT to various concentrations of NO₂; (F) Reproducibility and (G) long-term stability of CuO-PANI-2 at RT to 100 ppm NO₂; (H) Effect of RH on the gas-sensing responses of CuO-PANI-2 to 100 ppm NO₂ gas at RT; (I) Selectivity of CuO-PANI-2 sensor to 100 ppm of various interfering gases at RT. RT: Room temperature; PANI: polyaniline; RH: relative humidity.