Co-precipitation synthesis of nanocrystalline SnO2: Effect of Fe doping on structural, morphological and ethanol vapor response properties

• 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 Fe doped SnO2 for ethanol vapor detection.

The present study describes undoped and Fe-doped tin dioxide thick films as selective ethanol vapor sensors. The undoped and Fe doped SnO2 powders were synthesized by using a facile co-precipitation route. The thick films of undoped and Fe-doped SnO2 were deposited by screen-printing technique and then sintered at 650 °C for 2 h. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) techniques. The XRD studies reveal formation of nanocrystalline structure. The particle size of undoped and Fe (2 and 4 mol%) doped SnO2 sintered powders were 17, 10 and 8 nm, respectively. It was found that the response of SnO2 improved on addition of Fe. The 2 mol% Fe doped SnO2 exhibits highest response toward ethanol at the operating temperature of 300 °C with response and recovery time of 15 and 32 s, respectively.