Figure 4. Gas-sensing performance for the SnO2 HNSs-1 and HNSs-3.
(a) sensitivity and (b) response and recovery time of two sensors to 10 ppm NO gas at different working temperature; (c) The real-time response curve of three sensors to NO gas with increased concentration at a working temperature of 200°C; (d) The relationship between the sensitivity and the NO concentration; (e) Sensor response to various gases with 10 ppm at 200°C.