A novel amperometric NO2 sensor based on nano-structured La0.75Sr0.25Cr0.5Mn0.5O3−δ–Ag composite sensing electrode prepared by impregnating method

An amperometric NO2 sensor using nano-structured La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM)–Ag composite sensing electrode with Ce0.9Gd0.1O1.95 (CGO) electrolyte was fabricated. The LSCM–Ag particles in the range of 100–200 nm were prepared in the porous CGO layer by impregnating method. The NO2 sensing characteristics were examined. The sensor showed high response to NO2 and the response current was almost linear to NO2 concentration at 400–600 °C. With the Ag loading level increased, the sensitivity of the sensor increased remarkably and the best performance was observed at the LSCM/Ag molar ratio of 1:0.5. The response current was slightly affected by changing O2 concentrations in the range of 0–10 vol%.

► We developed an amperometric NO2 sensor using LSCM–Ag composite sensing electrode.
► Nano-structured LSCM–Ag sensing electrode was fabricated by impregnating method.
► The sensor showed good sensitivity to NO2 at 400–600 °C.