Electrospinning Fabrication And Gas Sensing Properties Of One Dimensional Fe₂O₃/SnO₂ Nanowires

With the industrialization rapidly developing today, the air quality problems have drawn the attention by the domestic and international society unprecedentedly. Some families and people in public places have started to use air purification and monitoring equipment. Whether to control the air pollution from the source or improve air quality gradually, the gas sensor plays an essential role in it. The semiconductor gas sensor has a great potential for development due to low cost, high flexibility and easy to use. It can be used as a portable device in a specific area of gas detection. Because of its low cost, it can be largely deployed in environment and multiple gas sensors can coordinate with each other in network. In this way, we could build the environmental information society. In addition, we can also combine new type semiconductor materials with modern microelectronic processing technology in order to develop new miniature gas sensor.Researches in semiconductor gas sensor involve knowledge between electronics, physics and chemistry. The first chapter in this article expounds the three characteristics of semiconductor gas sensor(recognition function, transfer function and utilization rate of sensitive body) from two angles of qualitative and quantitative factors. It also discusses the factor affecting the performance of gas sensor and how to use the electrostatic spinning technique to prepare the good sensitive material. In the second chapter in this paper, it introduces that we prepared iron oxide and tin oxide composite nanowires which compose of 10 to 30 nm nanoparticles by electrostatic spinning technology. Through changing the electrostatic spinning precursors and taking thermal weightlessness tests, we speculated the mechanism of by-products formation. Then we prepared the gas sensor with above sensitive material and it showed extremely fast response times to acetone gas(1.5 seconds) and recovery time(4 seconds), which mainly depended on the hollow porous nanostructure. At the same time, the experimental test results showed that the working temperature of the gas sensor has an important influence on its selective property. In the third chapter of this paper, we prepared the tin oxide nanowires modified with iron oxide nanoparticles by electrostatic spinning technology. Then we combined the sensitive material with the planar device through hot pressing technology. For ethanol gas testing we found that the response of the as-prepared product increased 4 times compared with the unmodified tin oxide nanowires. It mainly depended on the alkaline surface modification function of iron oxide. In addition, we also speculated the formation mechanism and the sensing mechanism of the material. The fourth chapter is the conclusion and the outlook.