Investigation of Electrical and Gas Sensing Properties of CeO2 Nanoparticle Synthesized by Precipitation Method

In the present research work, pure CeO₂ nanoparticles (NPs) were successfully synthesized using the precipitation method with cerium (III) nitrate hexahydrate [Ce(NO₃)₃·6H₂O] as a precursor. The synthesized CeO₂ NPs were employed to fabricate thick films via the standard screen-printing technique, and their electrical as well as gas sensing properties were systematically studied. The prepared CeO₂ thick films exhibited a resistivity of 5939.03 Ω/m with a negative temperature coefficient of resistance (TCR) value of –0.002815 /°C, confirming their semiconducting behavior. The activation energy values were found to be 0.0546 eV in the low-temperature region (LTR) and 0.2421 eV in the high-temperature region (HTR). Gas sensing analysis revealed that the CeO₂ NPs thick films showed maximum response toward NH₃ gas, with a sensitivity of 76.95% at 120 °C for 1000 ppm concentration, along with fast response and recovery times. These results suggest that CeO₂ NPs thick films are promising candidates for efficient and selective NH₃ gas sensing applications.