Аннотация:Nanocrystalline LaCoO3 was synthesized by sol-gel method and functionalized by Agnanoparticles via impregnation. An improved sensitivity to H2S gas was detected for theAg/LaCoO3. The nanocomposite sensors showed lower cross-sensitivity to CO and NH3, incomparison to pure LaCoO3. The role of Ag nanoparticles in promotion of the H2S adsorption andoxidation on the surface of LaCoO3 was elucidated using diffuse reflectance infrared Fouriertransformed(DRIFT) spectroscopy.