Study On The One-dimensional Structure Design Of Nanomaterials And Their Gas Sensing Propetries

In recent years, with the development of industrialization and the increase of thepopulation, the emissions of many kinds of harmful gases are threat to human beingsenvironment. In order to overcome these threats and challenges, it is very importantthat to research and develop the gas sensors for environment monitoring. Gassensitive material is a heart part for gas sensor. The type and morphology play animportant influence on the performance of the gas sensor. In recent years, with thedevelopment of nanotechnology, the gas sensitive material of low dimension andporous is the development direction of the future. One-dimensional nanomaterials canincrease the sensitivity of gas sensitive materials due to their high specific surfacearea, large ration of length-diameter and the directionally conductive of electrons.These advantages also have a big effect on response and recovery times.One-dimensional nanomaterials show a good application prospect in the field of gassensor. However, the gas sensor base on one-dimensional pristine semiconductoroxide often has a poor sensitivity. The gas sensing properties can be effect by controlthe morphology and composition of nanomaterials.In this work, some kinds of one-dimensional metallic oxide nanomaterials wereprepared by electrospinning technic. Their gas sensing properties were investigated.The composition and morphology were improved to improve the sensitivity. Theapplications of metallic oxide nanomaterials are expanded in the field of environmentmonitoring. The concrete contents are exhibited as follows.1. In2O3one-dimensional nanowires and nanotubes were synthesized byelectrospinning and its gas sensing properties were investigated by its gas sensors.The results reveal that the sensitivity of In2O3nanowire and In2O3nanotube to100ppm acetone are14.2and23.5at280℃. In2O3nanotube shows a better sensitivity toacetone.2. Co-In2O3nanowires and nanotubes were synthesized by electrospinning. Theirgas sensors were made to investigate their gas sensing properties. The response of Co-In2O3one-dimensional nanotubes is93.1to100ppm ethanol at260℃. Theresponse is2.24times larger than Co-In2O3one-dimensional nanowire with theresponse of41.5. The response and recovery time of Co-In2O3one-dimensionalnanotubes are3s and72s. Moreover, Co-In2O3one-dimensional nanotubes show agood selectivity to ethanol.3. The pristine In2O3and Fe2O3-In2O3one-dimensional nanotubes weresynthesized by electrospinning. Their gas sensors were made to investigate their gassensing properties. The results reveal that the response of Fe2O3-In2O3one-dimensional nanotubes sensor is33.33to100ppm formaldehyde at250℃. It is2.1times larger than pristine In2O3nanotubes sensor with the response of15.78. Theyhave the same response and recovery times. The response and recovery times are5sand25s, respectively. The limit detection is1ppm with the response of2.12.4. The pristine In2O3and ZnO-In2O3one-dimensional nanotubes weresynthesized by electrospinning. Their gas sensors were made to investigate their gassensing properties. The results show that ZnO-In2O3one-dimensional nanotubessensor have a good sensitivity to acetone. The response is43.2to60ppm acetone at280℃. It is about3times larger than pristine In2O3nanotubes sensor. The responseand recovery times are5s and25s. The limit detection is0.125ppm with the responseof2.04. ZnO-In2O3one-dimensional nanotubes sensor also show a good selectivity toacetone.5. WO3nanotubes were synthesized by single nozzle electrospinning. Gassensors were made to investigate their gas sensing properties. The results show thatWO3nanotubes sensor has a good sensitivity to acetone. The response is about45to100ppm acetone. The response and recovery times are5s and22s. The limit detectionis0.5ppm acetone with the response of2.5. WO3nanotubes sensor show a goodselectivity to acetone. The response is6times larger than100ppm ethanol to100ppm acetone. They can be distinguished by response. WO3nanotubes sensor have agood selectivity.