MODIFICATION OF SnO2 NANOWIRES BY Cu(NO3)2 SOLUTION DROPPING FOR ENHANCING H2S SENSING CHARACTERISTICS

Abstract

CuO nanoparticles modified SnO₂ nanowires were fabricated by dropping copper nitrate aqueous solution onto SnO₂ nanowires as-prepared on Si/SiO₂ electrodes. The CuO-modified SnO₂ nanowires had a superior H₂S response in comparison with raw SnO₂ nanowire sensors. At 250 °C, the R_a/R_g values of the raw SnO₂ nanowires to from 0.25 to 2.5 ppm H₂S were from 1.6 to 2.36 respectively, while CuO-modified SnO₂ nanowires responses to the same concentrations of H₂S were from 1.7 to 531. In addition, at the working temperature of 150°C, the H₂S responses of the CuO-modified SnO₂ nanowires increase sharply from 66 to 2023 depending on the gas concentrations (0.25-2.5 ppm). The results show that the modification of SnO₂ nanowires with CuO not only increases the response to H₂S gas but also reduces the working temperature of the SnO₂ nanowire sensor.