| Recently,with the rapid development of flexible devices,researchers have carried out extensive and in-depth research based on flexible supercapacitors and electrochemical sensors,which have put forward higher requirements for the electrochemical and mechanical properties of materials.Conducting polymers have aroused extensive research due to excellent performance.Based on conductive polymers and their composite materials,the thesis has carried out application research in flexible supercapacitors and electrochemical sensors.The electrochemical performance,microstructure,and sensing performance of the composite materials were characterized using conventional electrochemical methods and micro-test methods.The thesis has positive significance for the design and synthesize of conductive polymer-based composite materials and its application in flexible devices.The main research contents are summarized as follows:?1?Conductive polymer hydrogel has excellent electrochemical responsiveness,flexibility and conductivity,it can be used to fabricate flexible electrode materials,which is very important for the assembly of flexible wearable sensors.We synthesized PANI-CNT composite hydrogel by self-assembly strategy for nitrite detection.CNT is closely adsorbed on PANI hydrogel with three-dimensional porous layered microstructure through?-?interaction to form PANI-CNT composite hydrogel.The three-dimensional porous structure of PANI hydrogel and the excellent electrical conductivity of CNT greatly promote the diffusion and transfer of electrolyte ions.At the same time,PANI-CNT hydrogel has excellent hydrophilicity,which can promote the effective contact between electrode and electrolyte.The electrochemical sensor based on PANI-CNT hydrogel modified eletrode can be effectively used to detect nitrite.The linear detection range is 20?M to 1.8 mM,and the detection limit is 7.8?M.In addition,The PANI-CNT hydrogels were coated onto printed electrode,and successfully designed a flexible electrochemical sensor for nitrite detection.The flexible sensor showed high sensitivity(254.54?A mM-1cm-2).PANI-CNT hydrogels have great potential in the design of flexible and wearable sensors,in which the composite hydrogels can act as both a sensor and an electrolyte storage unit.?2?Nitrogen-doped graphene?NG?is an important class of electrode materials for supercapacitors.In this work,we reported flexible free-standing film by nitrogen-doped graphene and conductive polymer PEDOT,and assembled flexible supercapacitors.Based on the flow-directed self-assembly of PEDOT:PSS and NG mixed solution,through a simple filtration method,we prepared NG/PEDOT composite film electrode material.The conductive polymer PEDOT component acts as a binder in the process of filtration.On the one hand PEDOT increases the conductivity of the composite film,on the other hand PEDOT reduces the accumulation of NG.Nitrogen-doped graphene improves the electrochemical performance by introducing pseudocapacitors.Meanwhile,it can effectively prevent the stacking of graphene sheets and improve its utilization rate.Therefore,the nitrogen-doped graphene and conductive polymer PEDOT gives this composite film high conductivity,hydrophilicity and excellent electrochemical performance(535.51F·g-1 at 0.5 A·g-1).The free-standing films are also used as electrode materials,current collector,and mechanical support to fabricate flexible all-solid supercapacitor with the specific capacitance of 206 F·g-1 at 0.25 A·g-1.?3?The NG/PEDOT composite has great potential in the electrochemical sensor due to its excellent catalytic properties,hydrophilicity and conductivity.In this work we used NG/PEDOT composite modified electrode for the detection of dopamine.Under optimized conditions,the NG/PEDOT composite modified electrode presents high stability,good conductivity,excellent electrocatalytic performance,and shows favorable selectivity,high sensitivity(0.9?A mM-1 cm-2)for dopamine detection,with a linear range from 0.2?M to 90?M,a detection limit of 54 nM. |
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