Design And Synthesis Of Doped Zinc-based Oxides And Their Gas Sensing Properties

Gas sensors are commonly used to monitor and detect toxic,harmful,flammable gases and have been widely used in people's lives.As the heart of gas sensors,gas sensing materials are the key part for high performance gas sensor.Metal oxide semiconductors are favored by many researchers because of their advantages of being non-toxicity,easy preparation,low cost,high sensitivity,and wide selectivity.However,they also have some disadvantages of high working temperature and low selectivity.Therefore,this paper aims to improve the gas sensing performance of gas sensing materials,improve its operating temperature and poor selectivity,and carry out research work on the composite and improved structure of metal oxide semiconductors.The work is as follows:1.ZnO/ZrO2/PVP precursors with different amount Zr elements of 5 mmol%,10 mmol%,15 mmol%,20 mmol%,and 25 mmol%were prepared by electrospinning method,and calcined at 800? to obtain different proportions of ZnO/ZrO2 composite metal oxide.Firstly,we explored the gas-sensitive properties of different proportions of Zno/ZrO2 composite metal oxides to 100 ppm n-butanol;Secondly,we explored the effect of operating temperature on the sensitivity of Zno/ZrO2 composite metal oxides.Furthermore,we investigated the gas-sensing properties of Zno/ZrO2 composite metal oxides to 100 ppm n-butanol at different calcination temperatures of 600?,800?,and 950?;Finally,we explored the selectivity of 15 mmol%ZnO/ZrO2 composite metal oxide calcination at 800? for 100 ppm other volatile gases.The results show that 15 mmol%of Zno/ZrO2 eomposite metal oxide has the highest sensitivity to 100 ppm n-butanol after calcination at 800?,and its value is 107,and the operating temperature is 245?.2.Preparation of ZnNi flake structure metal oxide and its detection and application of gas sensitivity to triethylamine gas.The precursor of the sheet structure was grown in situ on the surface of the ceramic tube by simple hydrothermal synthesis,and the metal oxide ZnNixO(where x represents the actual molar ratio of the Ni element)was obtained after high temperature calcination,and the surface roughness and the specific surface area are still retained sheet structure.The results show that the doping of an appropriate amount of Ni element into the ZnO to form a sheet-like structure,its shape is flat,uniform,and small pores,the atom utilization rate is relatively high,which helps to improve the gas sensitivity of triethylamine gas properties;The presence of the Ni element makes the surface of the sheet structure rougher,and the gas sensitivity of the ZnO group is remarkably improved.Among them,the sample ZnNi0.1O-600 has the best gas sensitivity to 100 ppm triethylamine,and its sensitivity value is 100.