The Preparation Of Metal Oxide Composites And The Investigation Of Gas Sensing Performance

Due to the fast response and low concentration of detection toward flammable and poisonous and harmful gas, gas sensor has many important applications in the field of chemical production, environmental monitoring. Metal oxide semiconductor, as an important part of gas sensor, detects different kinds of gas by change the resistance of material due to the adsorption and desorption of gas, However these materials remain these drawbacks such as low sensitivity, the minimum detection limit and high detection temperature. In order to further improve the material gas sensitive response, the researchers conducted a series of exploration around these directions.This paper prepare rare earth doped indium oxide nanocomposites and cuprous oxide supported in graphene with the goal of the controllable preparation and the enhancement of gas sensing maerial. The doping and load effect on the properties of gas sensor were investigated, and the reaction mechanism of gas sensitive were explored. The main contents are included:1 Rare earth (Tm, Er, La, Yb and Ce) doped In2O3 nanostructures with three-dimensionally ordered macroporous structure (3DOM) were prepared by colloidal crystal templating method with PMMA microspheres as a template. The morphology, composition and structure of the material defects were analyzed by SEM?TEM?XRD?TGA?Raman?ICP?EDS?XPS. The calcination temperature, doping elements and doping proportion on the impact of gas sensitive performance were investigated. The doping of five kinds of lanthanum rare earth elements (Tm, Er, La, Yb, Ce) on 3DOM structure of indium oxide on the response characteristics of ethanol were researched. Tm doped indium oxide with the best performance was selected to further optimize the doping ratio of rare earth elements.2 The GO was synthesized through the improved Hummers method, and Cu2O-RGO hybrid materials though hydrothermal method. The characteri-zation of the structure and morphology of materials were analyzed by AFM,IR, raman, XRD, and XPS. These two different morphology Cu2O-RGO hybrids gas sensing property were tested to NO2 gas and deduce the mechanism of gas sensing, which provided an effective way to detect detrimental and poisonous gases at room temperature rapidly.