Preparation And Gas Sensitive Properties Of Composite Nanofibers Based On Nickel Oxide Hollow Structure

In recent years,in the field of gas sensing,the development of nanotechnology has injected new directions for the research of sensitive materials.Metal oxide composite nanofibers have broad application prospects in the field of sensors,because composite materials can combine the advantages of materials with different physical and chemical properties into one.By changing the composition of the composite material,the selectivity of sensitive materials can be improved,and the fiber itself The network structure increases the active sites of sensitive materials in contact with gas,increases the specific surface area of sensitive materials,and thereby increases the sensitivity to gas..In this paper,based on the microstructure and composition control of NiO nanofibers,the preparation processes of Fe/NiO,Fe₂O₃/NiO,and In₂O₃/NiO nanofibers with three-dimensional hierarchical structure were studied respectively,and study the gas-sensitive properties of ethanol.The main research work of this article is:(1)Under normal temperature conditions,based on electrospun PAN nanofibers and carbonized carbon fibers as templates,a simple co-precipitation method was used to prepare hollow Fe/NiO nanofibers,and the recovery time from sensitivity and response The gas-sensitivity performance of the product is discussed in other aspects.The sensitivity of the prepared Fe/NiO nanofibers to 100 ppm ethanol at 400?is 3.87,which is slightly higher than that of pure NiO.(2)Using chemical deposition method,carbonized carbon fiber as template,prepared Fe₂O₃/NiO composite nanofibers with stable hollow structure,and tested the gas sensitivity of ethanol gas.The test results show that when the Fe³⁺concentration is 7.7 m mol L^-1,the prepared Fe₂O₃/NiO composite nanofibers exhibit the best gas sensing performance.The response to 100 ppm ethanol gas at 280?is 10.81,which is about 7 times the sensitivity of pure NiO.This is mainly due to the effective binding and surface modification between n-type Fe₂O₃and p-type NiO.(3)Based on the synthesis of Fe₂O₃/NiO hollow nanofibers,the hollow In₂O₃/NiO nanofibers were synthesized with In(OH)₃with a small K_spvalue after cation replacement according to the dynamic equilibrium of ions in solution.The sensitivity of the prepared In₂O₃/NiO composite nanofibers to 100 ppm ethanol gas at 280?is 3.58,which is about 2.5times that of NiO hollow nanofibers.In this paper,we systematically discuss the control of the microstructure and composition of nanofibers by controlling the preparation methods of based on NiO composite semiconductor nanofibers through the above three aspects,and deeply study the gas-sensitive mechanism of metal oxide composite concentration on sensitive materials.The effect of this method provides a new idea for the preparation of metal oxide composite nanofiber sensors.