Inkjet Printable Electrochemical Sensing And Energy Storage Devices Based On Nanocomposites

For a long time,portable,highly integrated electrochemical sensing and energy storage devices have attracted the attentions of a wide range of researchers around the world.At present,the main limitation of electrochemical sensing and energy storage devices in large-scale application is the lack of a fast,convenient and low-cost processing means to transform laboratory research into industrial products that can be used with a large scale.Inkjet printing,as a non-contact,high precision,dropon-demand means,provides a possibility which makes electrochemical sensing and energy storage devices for large-scale industrial processing.In this thesis,an electrochemical sensor chip with high sensitivity and an electrochemical supercapacitor with high capacity are prepared by combining inkjet printing and new nanocomposites.This thesis reviews the history of inkjet printing,introducing the conductive polymer and its application in inkjet printing,and discussing the research of inkjet printing in sensing and energy storage field.The inkjet printing technique owns lots of advantages,such as fast printing,low cost,non-contact etc.We explored the inkjet printing in the sensing field,followed by its application in the fabrication of supercapacitor,enriching the inkjet printing research contents.The main contents are summarized as follows:1.Fabrication of planar three-electrode chip by inkjet printing and its application in sensingThe synthesis of nano gold ink was carried out by using 3-mercaptopropyl and 6-mercaptohexanoic acid as the stabilizer.Gold nanoparticles were prepared by mixing noble metal compound,such as gold chloride acid,with mercapto compounds,followed by introduction of sodium borohydride as the reduction reagent.Inkjet printing technique was used to synthesize nanogold and silver electrode.Then,the silver electrode was immersed in sodium chloride solution to produce Ag/Ag Cl reference electrode,which can be used to replace the commercial Ag/Ag Cl reference electrode.After sputtering platinum electrode on the chip with a sputtering instrument,we have prepared the planar three-electrode chip.In order to verify the effectiveness of the planar three-electrode chip,we deposited different sensing materials on the gold electrode to detect melamine and dopamine.The results of the tests are consistent with the commercial three-electrode sensing system,which can meet the requirements of daily application.Compared to the ordinary three-electrode system,the chip owns higher sensitivity and a lower detection limit.2.Fabrication of flexible supercapacitor by inkjet printingIn this work,graphene oxide and polyaniline were prepared by modified Hummers method and micro-emulsion method,respectively.Graphene oxide and polyaniline were mixed in an ice-water bath to obtain the composite materials.Then,the composites were printed on a gold film substrate by inkjet printing,followed by reduction with H3PO2.The morphologies of the composites are studied with XRD,RAMAN,FT-IR,FESEM and AFM.Then we have discussed the performances of the supercapacitor.The results show that the composites of graphene and polyaniline are used as supercapacitor materials,which have high specific capacitance and good cycle stability.