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

The pyrosol spraying deposition technique has been used for the synthesis of SnO2, SnO2-CuO and SnO2-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 SnO2, SnO2-CuO and SnO2-NiO polycrystalline films with the reducing gases: H2S, C2H5OH, CO and CH4 has been investigated by conductance measurements. It has been found that copper and nickel have a significant effect on the sensitivity of SnO2 films to H2S. The model of interaction of SnO2 films with H2S 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.