A GdAlO3 Perovskite Oxide Electrolyte-Based NOx Solid-State Sensor

Abstract

NOx is a notorious emission from motor vehicles and chemical factories as the precursor of acid rain and photochemical smog. Although zirconia-based NOx sensors have been developed and showed high sensitivity and selectivity at a high temperature of above 800 °C, they fail to show good performance, and even don’t work at the typical work temperature window of the automotive engine (<500 °C). It still is a formidable challenge for development of mild-temperature NOx detector or sensor. Herein, a novel amperometric solid-state NOx sensor was developed using perovskite-type oxide Gd1−xCaxAlO3−δ(GCA) as the electrolyte and NiO as the sensing electrode. NOx sensing properties of the device were investigated at the temperature region of 400–500 °C. The response current value at −300 mV was almost linearly proportional to the NOx concentration between 300 and 500 ppm at 500 °C. At such a temperature, the optimal sensor gave the highest NO2 sensitivity of 20.15 nA/ppm, and the maximum response current value reached 5.57 μA. Furthermore, a 90% response and 90% recover time to 500 ppm NO2 were about 119 and 92 s, respectively. The excellent selectivity and stability towards NOx sensing showed the potential application of the sensor in motor vehicles.

Alkaline-Earth Metals-Doped Pyrochlore Gd2Zr2O7 as Oxygen Conductors for Improved NO2 Sensing Performance

“…Unfortunately, Gallium has a volatility, which greatly restricts the application of such sensor in NO 2 detection too. Inspired by the studies on doped LaGaO 3 above, we have recently reported the NO 2 sensors based on perovskite-phase GdAlO 3 substrates, in where Ca was arranged at A-sites 18 . However, the response and recovery time is very long in excess of 119 and 92 s, respectively.…”

Hoisting the photovoltaic performance by photocharging and plasmonic effect via aminosilane‐protected silver/barium titanate for dye‐sensitized solar cells

“…Alternatively, other photoanodes such as ZnO, 5 Nb 2 O 5 , 6 and WO 3 7 has been explored. Recently, oxide perovskites opened up a new era in the area of photocatalysts, 8 capacitors, 9 and sensors 10 owing to its unique properties. Also, they are found to be potential material due to their anomalous behavior compared with conventional TiO 2 ‐based DSSC 11 .…”

Enhanced NO2 Sensing Property of ZnO by Ga Doping and H2 Activation

“…The pollution of poisonous gases, such as NO 2 from the burning of fuel and the exhaust from the city autos, poses a great threat to both the environment and people's health. Therefore, it is highly desired to develop fast detection techniques for air quality assessment . Semiconductor‐based gas sensors such as SnO 2 , TiO 2 , ZnO, and so on have attracted numerous attention because of the advantages of in situ detection, fast responses, low cost, long stability, etc .…”