Preparation And Gas Sensing Properties Of Tin - Based Nanocomposites

As new sensing material, thanks to its good performance, SnO2 gas sensor iswidely used in various fields. The gas sensing performance of SnO2 is affected by the impact of the structural parameters, such as morphology, size, crystallinity and internal structure. By appropriate doping, SnO2 can improve its selectivity and sensitivity to reduce experimental cost. This article is prepared by the solvothermal method of doping metal ion or other nanomaterial to modify SnO2 performance. The main research work is as follows:1.The synthetized SnO2 nanocomposite with 3D hierarchical structure by change of the Sn4+ concentration. The material has good gas sensing response to NOx at room temperature. The sample SN-3 has the fastest response and the highest sensitivity to 97 ppm NOx, the response time is 9.3 s and sensitivity is 14.85, its limit level is 0.485 ppm.2.Combination of doped principle, SnO2 doped indium ions has been prepared by using the solvothermal treatment method. The crystal structure composition, grain size and morphology are characterized by SEM, TEM, XRD, XPS, EIS and MS analysis means. The result shows that the increasing of the dopant can result the specific surface area increased.The indirect heating gas sensors are prepared using SnO2 nanomaterials. When the doping ratio of 100:1, the components show better gas sensing properties. Futhermore, the SIF-2 sensor exhibits excellent gas-sensing properties that are low detection limit of 0.097 ppm, high sensitivity of 33 to 97 ppm NOx.3.The synthesized with SCF composite with the mass ratio of 30:1 for SnCl2/Cu(NO3)2(SCF) contained a lot of oxygen defect sites. The porous hierarchical nanostructures provide natural channels for the effective and fast transportation of carriers.The SCF-2 sensor exhibits excellent gas-sensing properties that are low detection limit of 0.97 ppm, high sensitivity of 90 to 97 ppm NOx.In summary, the SnO2,SCF and SIF with 3D hierarchical structure with highly mesoporou hierarchical have fast-response to NOx at room temperature. It look forward to promising material in gas sensing field.