Effect of calcination temperature on sensing performance of YSZ based electrochemical H2S gas sensor with a NiFe2O4 electrode

Abstract

Electrochemical gas sensors based on yttria-stabilized zirconia (YSZ) film have attracted ascending attention for detecting H2S. Due to the poor sinterability of YSZ film, high-temperature calcination is usually required in the preparation procedure to ensure the good contact between YSZ and sensing electrode, which could particularly limit the triple phase boundary (TPB) length at the interface of H2S|YSZ|sensing electrode as well as the porosity of sensing electrode. Therefore, the calcination temperature would significantly affect the sensing performance, which has been ignored in reported studies. In this work, YSZ based electrochemical gas sensors with NiFe2O4 (NFO) sensing electrode are prepared to detect H2S at ppb-level. The effect of the calcination temperature of NFO sensing electrode on the sensing performance is investigated. The sensor with an optimal calcination temperature of 1000 °C delivers a response value of − 42 mV for 500 ppb H2S at 460 °C with a detection limitation of 10 ppb H2S. Good linear slopes with a sensitivity of − 13.1 mV/decade toward 20–100 ppb H2S and a sensitivity of − 46.9 mV/decade toward 100–500 ppb H2S are obtained. Meanwhile, the sensor also displays attracting stability and short response/recovery time. The good sensing performance is attributed to enhanced TPB length, good porosity of NFO electrode and limited interaction between the NFO and YSZ film by optimizing the calcination temperature of NFO sensing electrode.