| Polyaniline(PANI)is a kind of conductive polymer material with good conductivity,unique doping mechanism,and special photoelectric properties.Hydrogel is a 3D material with large surface area,porous and soft.Conductive polymer hydrogels combine the advantages of both and are widely used in both supercapacitor and sensor fields.Today’s supercapacitors have problems such as electrolyte solution leakage,high cost,and are only suitable for DC applications.Moreover,there are few researches on photosensitive sensors.Therefore,this article first studied the conductivity and photosensitivity of polyaniline powder.Then,polyaniline and hydrogel were polymerized to explore its electrochemical ability and photosensitivity.Therefore,a flexible polyaniline-based hydrogel with great potential in the field of supercapacitors and sensors is proposed.(1)Taking the concentration of doped acid as a variable,a series of poly aniline with nanosheet and nanofiber structure were synthesized by chemical oxidation method.The results showed that when acetic acid:aniline=7:9;hydrochloric acid:aniline=2.5:5;citric acid:aniline=3:5,the conductivity and capacitance of polyaniline are both the best.The specific capacitance can reach 162.5 F/g,271.25 F/g,240.99 F/g,respectively.Then,by changing the wavelength of the monochromatic light irradiated on the photosensitive sensor,it was found that the nanorod-shaped polyaniline photosensitive sensor chip has excellent sensitivity to green light and blue light.Moreover,it was found that the photocurrent generated by the sample doped with appropriate concentration of hydrochloric acid can be close to 10-6 A.Therefore,PANI has great potential in the field of photosensitive sensors and supercapacitors.(2)A flexible hydrogel was prepared by in-situ polymerization with polyvinyl alcohol(PVA)hydrogel as substrate and polyaniline as active substance.Compared with the PANI-interdigital electrode sensor,the prepared polyaniline-polyvinyl alcohol(PANI-PVA)hydrogel can generate a photocurrent of about 10-5 A or 10-4 A under external light stimulation,which is about 1 to 2 orders of magnitude higher than the photocurrent of the interdigital electrode sensor.It shows that the flexible PANI-PVA hydrogel is more sensitive to light stimulation.Moreover,in the process of preparing PANI-PVA hydrogel,adding an appropriate concentration of acid can better distinguish the external light stimulation.In addition,the electrochemical performance of the galvanostatic charge-discharge(CP)data of the PANI-PVA hydrogel was analyzed to obtain the specific capacitance of the hydrogel.After doping with 0.75 mol/L acetic acid,0.60 mol/L hydrochloric acid,and 0.024 mol/L citric acid,the maximum values of specific capacitance are 684.75 mF.cm-2,525 mF.cm-2,and 524.75 mF.cm-2,respectively.The results show that the flexible PANI-PVA hydrogel prepared without affecting the energy storage capacity and photosensitivity has a wider application range.However,the preparation of PVA hydrogels takes a long time,requiring 8 hours,and requires a lot of aniline(0.1 mol),and the tensile properties after molding are not good.(3)Using polyacrylamide(PAM)hydrogel as substrate material and polyaniline as active substance,a flexible conductive hydrogel was synthesized by in-situ polymerization.Under external light stimulation,the photocurrent generated by the prepared polyaniline-polyacrylamide(PANI-PAM)hydrogel is about 1-2 orders of magnitude(10-5,10-4)higher than that of the interdigital electrode sensor,and the response to different wavelengths of monochromatic light is more obvious than that of the PANI-PVA hydrogel.Moreover,the electrochemical performance analysis of PANI-PAM hydrogel showed that after doping 0.0142 mol/L citric acid,0.18 mol/L hydrochloric acid and 0.116 mol/L acetic acid,the specific capacitance of PANI-PAM hydrogel can reach 388.25 mF/cm2,373.75 mF/cm2 and 276.25 mF/cm2.Compared with the prepared PANI-PVA hydrogel,PANI-PAM hydrogel can be prepared in a shorter time(2 h)and less raw material consumption(0.05 mol aniline),and its energy storage capacity and photosensitivity are not affected.Therefore,PANI-PAM hydrogel can be used in the field of supercapacitors and photosensitive sensors.Figure[35]Table[2]References[109]... |
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