Synthesis and Gas-Sensitive Chemoresistive Properties of TiO2:Cu Nanocomposite

Nanocrystalline TiO2 powder with an average crystallite and particle size of 11.6 ± 1.2 and 36 ± 2 nm, respectively, having anatase structure, has been prepared by the sol–gel method. The powder has been used for pen plotter printing of semiconductor coatings on a special sensor. The sensor surface has been modified with copper-containing nanoclusters using the AACVD method, and the elemental composition of the resulting composite coatings has been studied by the EDX method. TiO2 and TiO2:Cu receptor nanomaterials showed a high reproducible response to H2S at an operating temperature of 300°C. Copper doping of the TiO2 surface contributed to a significant increase in the response to high concentrations of H2S (the RAir/R response by 100 ppm H2S increased from 44.2 to 70.5) probably due to the formation of CuS groups on the surface of the receptor material. The modification of TiO2 with copper oxide led to a decrease in the oxygen sensitivity apparently because of a decrease in the number of active oxygen vacancies involved in the detection of oxygen.