The Research on Preparation and Gas Sensitivity of SnO2 /gold Composite Materials
|School||Huazhong University of Science and Technology|
|Keywords||nanoscale gold SnO2 nanoparticles SnO2/Au composite material gas sensor sensitivity|
Metal Oxides （MOX） have being drawn more and more attentions as gas sensing materials. Various strategies, such as doping, material nanosizing and incorporation of noble metals particles into metal oxide gas sensing materials, have been adopted to improve their sensitivity.In this work, Au nanostructures and SnO2 nano-crystals have been prepared by chemical method. The effect of preparation conditions on the morphology of Au nanostructures have been investigated. The TEM results show that, the morphology of Au nanostructures were decided by the molar ratio of the HAuCl4 and K2C2O4. With the decreasing of the ratio, the morphology of products gradually evolutes to spider-web-like architectures from nanoparticles.SnO2/Au composite material has been synthesized through chemical interaction between Au nanostructures and SnO2 nano-crystals. PH value is the decisive factor for its synthesis. The XRD results indicates that, SnO2/Au compisite material can formate under acidic conditions.Gas-sensitive performances of the prepared composite material have been investigated. The dependence of gas-sensitivity on gas concentration and operating temperature has been studied. Compared to SnO2 sensor, the sensitivity of composite material is improved, it elevates along with the gas concentration increasing. Moreover, the optimal response temperature for CH3CH2OH fall to 300℃from 350℃.