
Nanocomposites composed of SnO2 and CuO were prepared by hydrothermal method. The microstructures of obtained SnO2–CuO powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption–desorption test. The results show that the nanocomposites exhibited coral-like nanostructure, and the average crystalline size of SnO2 was 12 nm. The specific surface area of the four samples, SnO2–0.2CuO, SnO2–0.5CuO, SnO2–1.0CuO and SnO2–2.0CuO are 72.97, 58.77, 49.72 and 54.95 m2/g, respectively. The gas-sensing performance of the four samples to ethanol, formaldehyde and H2S was studied. The sensor of SnO2–0.5CuO exhibited high response to hydrogen sulfide (4173 to 10 ppm H2S, where ppm represent 10−6), and low response to ethanol and formaldehyde. The good selectivity exhibited that the SnO2–0.5CuO nanocomposite can be a promising candidate for highly sensitive and selective gas-sensing material to H2S.