The Constructions Of One-Dimensional Fe₂O₃-based Nanomaterials And The Gas Sensors' Performance Research

Since the reform and opening up,with the continuous development of industrial society,the people's standards for living have been greatly improved.At the same time,however,the problem of environmental pollution,especially air pollution,has become more and more serious and has affected people's daily lives.Monitoring and alarming of indoor and outdoor toxic and hazardous,inflammable and explosive gases accurate and timely,is a hot topic nowadays.Therefore,it requires a wide variety of gas sensors.As we know,the core of a gas sensor is the gas-sensing materials.Their type,composition,and structure all play a crucial role in the performance of the gas sensor.So far,metal oxide semiconductor?MOS?materials,such as Fe₂O₃,ZnO,and In₂O₃,are common gas-sensitive materials.Among them,Fe₂O₃ has received extensive attention due to its chemicalstability,economical,environmentalfriendlyandnon-toxicity.However,the poor gas sensitivity of pure Fe₂O₃ limits its further development.Inrecentyears,withthedevelopmentof nanotechnology,researchershavediscoveredthatcombining semiconductor materials with nanotechnology can significantly improve the gas-sensing properties of materials.At the same time,the low dimension of the material,the increase of the specific surface area,and the doping of other elements are all good ways to improve the gas-sensing properties of the material.In this paper,electrospinning method was used to prepare one-dimensional ironoxide-basedsemiconductor nanomaterials.By controlling the conditions of the experiment and the composition of the precursor solution,one-dimensional iron oxide-based semiconductor nanomaterials with different structures,shapes and doping ratios were prepared and fabricated into gas sensors to further study their gas-sensing properties.The details are as follows:1.Hollow and porous one-dimensional Fe₂O₃ nanotubes with diameters of about 100 nm were prepared by electrospinning method and gas sensors were fabricated to study their gas-sensing properties.The results show that pore formation on the surface of the material can significant improve its gas sensitivity.At the optimum operating temperature of240?,the porous Fe₂O₃ nanotube based gas sensor has a sensitivity of11 for 100 ppm acetone,which is about 3 times that of hollow Fe₂O₃nanotubes.Both of the materials have a fast response to acetone,the response time is about 9 s,porous Fe₂O₃ nanotubes have very short recovery time,which is about 3 s.At the same time,porous Fe₂O₃nanotubes also have good selectivity to acetone.2.Different doping proportions of Ho₂O₃-Fe₂O₃ composite nanomaterials were prepared by electrospinning method,then gas sensors were fabricated to study their gas-sensing properties.The results show that Ho doping can greatly improve the gas-sensing properties of Fe₂O₃ materials.3 wt%is the optimal doping ratio.The sensitivity of 3 wt%Ho₂O₃-Fe₂O₃nanomaterials to 100 ppm acetone at 240?is about 16.8 times than that of pure porous Fe₂O₃ nanotubes,is about 52.8 times of pure hollow Fe₂O₃nanotubes.The minimum detection concentration of acetone of 3 wt%Ho₂O3-Fe₂O₃ nanomaterials was 0.5 ppm and the response was 2.4.At the same time,it also has good linearity and selectivity.