Copper and nickel doping effect on interaction of SnO2 films with H2S

The pyrosol spraying deposition technique has been used for the synthesis of SnO 2 , SnO 2 –CuO and SnO 2 –NiO polycrystalline films with grain size of 3–10 nm. The composition, microstructure and electrical properties of the films have been investigated by X-ray diffraction, electron probe microanalysis, Auger electron spectroscopy and X-ray photoelectron spectroscopy. The interaction of SnO 2 , SnO 2 –CuO and SnO 2 –NiO polycrystalline films with the reducing gases: H 2 S, C 2 H 5 OH, CO and CH 4 has been investigated by conductance measurements. It has been found that copper and nickel have a significant effect on the sensitivity of SnO 2 films to H 2 S. The model of interaction of SnO 2 films with H 2 S gas and different sensor properties of tin dioxide films doped with copper and nickel are discussed with regard to the position of these metals in the films.