Synthesis, characterizations and gas sensing properties of nanocrystalline In2O3 thick film sensor

The nanocrystalline powder of In
2
O
3
with cubic structure prepared by a simple hydrothermal decomposition route. The structure and crystal phase of the powder was characterized by X-ray diffraction (XRD), microstructure by Transmission Electron Microscopy (TEM). The results indicated that the indium oxide was cubic with range size 28.5– 65.8 nm. Gas sensing properties of the nanocrystalline In
2
O
3
thick film sensor were tested for various gases in air at static state. The tested results showed that the sensor based on In
2
O
3
nanocrystals exhibited high response towards H
2
S gas (40 ppm) at an operating temperature 100°C. The selectivity of the sensor elements for H
2
S gas against different gases was studied. The results on response and recovery time were also discussed.