Detection of H2S down to ppb levels at room temperature using sensors based on ZnO nanorods

ZnO sensors were fabricated from ZnO nanorods prepared by a hydrothermal method and their gas-sensing properties were investigated. It was found that the phase composition of the product and the gas-sensing properties were dependent on the preparation conditions (the presence of surfactant and the ratio of V-ZnAc2(0.50M)/V-NaOH(5.0M)). The senior prepared at a ratio of V-ZnAc2(0.50M)/V-NaOH(5.0M) = 1 without any surfactant exhibited the best performance, which was characterized by high response and good selectivity to low concentrations of H,S at room temperature. The sensor also had a high response, high selectivity and short response time to low concentrations of C2H5OH at 350 degrees C. These characteristics make the sensor to be a promising candidate for practical materials detecting low concentrations of H2S and C2H5OH. Especially, the response to 0.05 ppm H2S attained 1.7 at room temperature. (c) 2005 Elsevier B.V. All rights reserved.