Study On The Preparation Of ZIF-8 Derived ZnO Nanomaterials And The Modification Of Butanol Gas-sensitive Properties

The semiconductor metal oxide type gas sensors have the advantages of low cost,excellent performance,simple operation.As we all know,the morphology and structures of materials have great influence on the performance of gas sensors.Moreover,the single metal oxide semiconductor materials have the disadvantages of poor selectivity and low sensitivity.Thus,A facile route to the synthesis of ZnO hollow polyhedrons semiconductor materials heterostructure based ZIF-8 as self-sacrificial templates by thermal decomposition at 400~?C is described,and based on the ZnO hollow polyhedron structure,some methods have adopted to improve gas sensing performance.The mainly research in two aspects:firstly,using the method of noble metal modified metal oxide semiconductor to improve the gas sensing properties of Zn O.Secondly,through in-situ doping method the Co-doped ZnO nanomaterials are prepared.The main work is summarized as follow:The ZnO hollow polyhedral structure materials are prepared through the ZIF-8 as self-sacrificing template and precursor,and the morphology,composition and structure of the materials are investigated by XRD,SEM,TEM,BET.Gas sensitive performance is tested based the Zn O hollow polyhedral material.The results show that ZnO hollow polyhedron materials have good gas sensing properties for butanol gas,which illustrate the ZnO hollow polyhedron materials have potential applications in the field of butanol gas sensor.Noble metal modification semiconductor metal oxide technology is used to enhance the gas sensing performance.The Pt modified ZnO nanomaterials are successfully prepared by photo deposition and their gas sensing properties are tested.The response of ZnO sensor to butanol is obviously improved by the modification of precious metal,and the sensitivity of the modified sensor is about 2 times that of the ZnO materials at the optimum operating temperature of 204 ~oC.The main causes of enhancement gas sensors performance are the electronic and chemical action of precious metals.The Co-doped ZnO hollow polyhedron materials by in situ doping technique are fabricated to improve the gas sensor properties.The effect of doping amount on the sensitive properties of ZnO is studied,and the optimum doping ratio is also investigated.The test results show that the response of the doped ZnO gas sensor is improved obviously.The 5%Co doped ZnO hollow polyhedron gas sensor has the highest responsivity to butanol.The main reason account for the increase of the response is that the local heterostructure is formed,thus the response of composites is increased.