Preparation Of Fe₂O₃-Based Heterojunctions Derived From Ferrocene-Based MOF And Their Gas Sensing Performance

With the rapid development of economy,it is urgent to develop easy,efficient and cheap gas sensors.In recent years,metal organic frame materials have been widely favored due to their many advantages,and the composite metal oxide gas sensors prepared by metal-organic framework as templates have developed more possibilities for gas detection,which is of great significance.Therefore,this paper mainly focuses on the preparation of composite metal oxide sensors based on iron doped metal-organic framework materials,and the detection of different analytical gases.The main research contents are as follows:（1）Using the zirconium-ferrocene metal-organic framework（ZrFc MOF）obtained by hydrothermal synthesis as a template and combined with r GO,theα-Fe₂O₃/ZrO₂composite material with mixed crystal phase and heterogeneous junction was obtained by high temperature annealing.The gas sensitivity of the material to acetic acid was investigated,and the gas sensitivity mechanism of the material was studied.The results show that Fe/Zr-4 has the highest sensitivity to 100 ppm acetic acid at 225°C,with superior selectivity and stability.（2）Using indium-ferrocene metal-organic framework（InFc MOF）as template,α-Fe₂O₃/In₂O₃ nanocomposites with n-n heterojunction were prepared by high temperature annealing at different temperatures.The cyclohexane gas sensing properties of In₂O₃/Fe₂O₃ calcined at different temperatures were investigated by Ag-Pd cross finger electrode as gas sensing element.The results show that the material has high gas response to cyclohexane.The response value of In-Fe-6 to 100 ppm cyclohexane at 225℃is as high as 86,which has a good linear relationship,good selectivity and repeatability.（3）A one-step hydrothermal method was used to synthesize nickel-ferrocene metal-organic framework（NiFc MOF）and then NiO/γ-Fe₂O₃ metal oxide semiconductor composites were prepared by high temperature annealing.The gas response of ethylene glycol was tested by using it as gas sensitive material.It has been shown that the Ni/Fe-4sensor has a response of 102 to 100 ppm ethylene glycol at 200℃,and has high selectivity and stability.This work also provides a new way for metal oxide semiconductor gas sensor to detect ethylene glycol gas.