Synthesis, characterization and LPG response of Pd loaded Fe doped tin oxide thick films

• Co-precipitation synthesis of pure and doped SnO2 for gas response application.
• Influence of doping on the gas response properties of SnO2.
• Variation in gas response properties with particle size.
• Potential ability of Pd loaded Fe doped SnO2 for LPG detection.

The nanocrystalline powders of undoped, Fe doped tin oxide and Pd (1, 2 and 3 mol%) loaded Fe: SnO2 were synthesized by co-precipitation method and characterized by using TGA–DTA, XRD, FE-SEM, EDAX, TEM, SAED, FTIR and Raman spectroscopy techniques. Gas sensing properties were investigated towards various reducing gases viz. liquid petroleum gas (LPG), ethanol, ammonia and acetone vapor. All the SnO2 compositions revealed single phase solid solution formation. The TEM and SAED results of samples sintered at 650 °C for 2 h show particle size of 19 nm for undoped SnO2 which was reduced to 5 nm on loading of Pd in Fe: SnO2. It is found that loading of Pd in Fe doped SnO2 reduces the particle size and improves the gas response. The gas sensing measurements showed that the 3 mol% Pd loaded Fe: SnO2 thick film sensor exhibited high response and good selectivity towards LPG at moderate operating temperature of 225 °C.