| SnO2 is a very excellent gas-sensitive material and is currently widely used in gas sensors.Improvements in the gas-sensitivity of the material can be achieved by means of doping and changes in morphology.The three-dimensional structure can increase the adsorption area of the surface of the material,thereby realizing the improvement of gas sensitivity characteristics.In this paper,the preparation of SnO2-Fe2O3 composite and its gas-sensitive properties to ethanol were studied.Firstly,flower-like SnO2 material and Fe2O3nanoparticles were prepared by hydrothermal method.In order to solve the problem of low adhesion between the material and the substrate,the two materials are added to the prepared Fe（OH）3 colloid and coated on the ceramic substrate by a spin coating process.The composite was obtained by annealing treatment.Gas-sensing elements of flower-like SnO2 gas sensors and SnO2-Fe2O3 composite materials gas sensors were prepared by vapor deposition of aluminum interdigital electrodes.The gas sensing properties of the two materials on ethanol were tested.It has been tested that the optimum working temperature of the flower-like SnO2 gas-sensitive material for 300ppm ethanol gas is 250°C,and the best working temperature of the SnO2-Fe2O3 composite material is 300°C;The sensitivity of flower-like SnO2 material to 300ppm ethanol is 38.5 when the working temperature is 250°C,while the SnO2-Fe2O3 composite material gas sensors is 43.5 at 300°C.In addition,the SnO2-Fe2O3 composite has the advantages of good response（10s）and recovery time（17s）to ethanol gas and good selectivity.The SnO2-Fe2O3 composite has good gas sensitivity to ethanol and is superior to the flower-like SnO2 material. |
