The Research Of Graphene Electrokinetic Character And Gas Sensitive Prototype Device Gas Sensitive Property

Since 2004, the graphene was proved to exist stability and independently, its special performance of electrical, mechanical, thermal and optical, laid the foundation of graphene in various fields. Such as electronics, nano composite materials, super capacitor, graphene composite transparent electrode, graphene touch screen, electrochemical sensors and biological medicine, etc. In the future, the development of preparation technology and application of graphene will change people’s life profoundly.In order to further study the possible application of graphene in nano electronic devices and gas sensor,by using monolayer graphene as the research object, which is researched the generation mechanism, features and possible applications of graphene electrokinetic phenomena,and the graphene gas sensor prototype device is prepare, then studied influence factors and gas sensitive performance of the gas sensor devices under different reducing gas atmosphere. As follows is the main content of paper research.(1) The crystal structure, morphology, composition, the number of layer and spectral information of graphene samples were researched with TEM, XRD, XPS, Raman analytic instruments, respectively. By comparing the testing parameters, crystal structure, the growth process, physical properties of monolayer and multilayer graphene, proved that the quality of graphene sample is high and single layer.(2) As monolayer layer graphene connected an external test circuit is the research object. Put the oxidized single crystal Si on a drop of ionic liquid droplets gently, which is on the grapheme, And the moisture adsorption phenomenon produced in the contact surface between Si and the droplet. Because the effect of electric double layer on the interface of ionic liquid and graphene, a 0.22 millivolts voltage can be induced in the external circuit by moving a droplet of 0.5M NaCl solution along a strip of graphene, it is the electric phenomenon. Studied the influence of induced voltage include different kinds of ions solution, different moving speed, different solution concentration, the number of droplets, the influence of the generation mechanism and analyzes the dynamic electricity phenomenon Studied the different ion solution, different moving speed is different, the same solution concentration, the number of droplets, and analyzes the generation mechanism and the dynamic electricity phenomenon. This study provides a certain application value for preparing graphene touch screen and a new graphene sensor.(3) Prepared gas sensor prototype device by the graphene based on PET substrate, which is connected electrode, and researched gas sensitive properties of reducing gas H2 and CH4, then analysised and discussed influence factors and mechanism of the gas sensitive device characteristics. With the increase of H2 and CH4 concentration, resistance and sensitivity of the device is increased. The sensitivity of the device is 80% and 70% respectively in H2 and CH4。The response-recovery time is 56 s, 84 s about H2, and CH4 is 67 s, 112 s. This study provides a experimental basis for the The development and application of graphene gas sensors.