Electrosynthesis Of Graphene/Polyindole And Investation Of The Electrochromic Properties

Graphene is one of the hottest interdisciplinary research spots in areas of material science,information science,bioscience,new energy and so on.It shows great prospect in new energy,electronics,catalysis,sensing devices,biomedical,optical and many other fields due to its great surface area and excellent electrical properties.Grapheme is under the spotlight of the science and technology community owning to its unparalleled properties.As nanofiller for polymer,grapheme has exceptional reinforcing efficiency towards polymer matrix,and it can endow the composites with functional properties.In this paper,two conducting composites,electrochemical reduction graphene/poly(5-formylindole)(ERGO/P5FIn)and graphene/poly(indole-6-carboxylic)(ERGO/PICA),have been prepared by electrochemical polymerization,and the electrochromic properties and its application in eletrochromic devices of the as-formed polymers are also investigated.1.A new conducting composite,electrochemical reduction grapheme/poly(5-formylindole)(ERGO/P5FIn),was synthesized by electrochemical polymerization of 5-formylindole(5FIn)monomer with ERGO modified electrode in acetonitrile(ACN).Spectroelectrochemical studies show that ERGO/P5 FIn can be changed from pale yellow(at 380 nm)to lawn green(at 500 nm)along with the change of potentials.Kinetic studies showed that it had a full optical contrast of 24.5 % at 380 nm.The time required for coloring was calculated to be 1.1 s and ERGO/P5 FIn exhibited a switch time to bleached state of 1.4 s at 380 nm.And the values were 42 %,0.8 s and 1.2 s at 500 nm,respectively.2.A dual type eletrochromic device(ECD)based on ERGO/P5 FIn and poly(3,4-ethylenedioxythiophene)(PEDOT)was also fabricated and showed a good electrochromic performance,a gradual color change from green-yellow to purple blue.The ECD constructed by ERGO/P5 FIn and PEDOT had coloration efficiency(382 cm2 C-1),fast response time(0.5 s and 1.2 s at 616 nm),high optical contrast(62 % at 616 nm),better optical memory and good long-term stability.3.Novel conducting nanostructured composite,electrochemical reduction grapheme/poly(indole-6-carboxylic acid)(ERGO/PICA),was synthesized by electrochemical polymerization of indole-6-carboxylic(ICA)monomer with ERGO modified electrode in acetonitrile(ACN).According to the results of cyclic voltammetry studies,ERGO/PICA composite film showedlow oxidation potential,high current density of peak and good electrochemical activity compared with PICA.Spectroelectrochemical studies showed that ERGO/PICA can be changed from bright-yellow(neutral)to jasper(oxidized)along with the change of potentials.4.Based on the excellent properties of graphene,a new type of electrochromic device was developed.The ECDs ERGO/PICA/PEDOT device and ERGO/PICA/ERGO device were fabricated,which were formed by PEDOT and ERGO as ion storage layer,respectively.And the electrochromic layers both are ERGO/PICA composites.The results of electrochemical studies show that the ERGO/PICA/ERGO device can be reversibly changed from yellow(-0.4 V)to green(1.8 V)with a light contrast of 51 % and a coloring efficiency of 538 cm2 C-1.Compared with the ERGO/PICA/PEDOT device,it is found that the device prepared with ERGO as the ion storage material have excellent electrochromic properties.