Preparation And Electrochemical Properties Of Three-dimensional Functionalized Graphene/polyaniline Composite Electrode Materials

Although three-dimensional graphene has many excellent properties,such as fast charging rate,long cycle life,abundant pore structure and high conductivity.However,its application in supercapacitors is greatly restricted,due to its low specific capacitance.The combination of polyaniline（PANI）and three-dimensional graphene can increase its specific capacitance,but the interface bonding between polyaniline and graphene is poor,which affects the electrochemical performance of the composite electrode materials.To solve these problems,a functional modification method is proposed in this paper.By modifying the surface of three-dimensional graphene with amino（-NH₂）and sulfonic acid groups（-SO₃H）to regulate and control the interface bonding mode between polyaniline and graphene,and the three-dimensional functionalized graphene/polyaniline composite electrode materials with good electrochemical properties were prepared by studying the microstructures and electrochemical properties of the composites.The mai n research contents are as follows:（1）Three-dimensional graphene（3D-G）was prepared by hydrothermal reduction with hydroquinone（HQ）as reducing agent,and three-dimensional graphene/polyaniline（3D-G/PANI）composite electrode material was prepared by in-situ polymerization.The effects of the amount of aniline（An）on the morphology and electrochemical properties of 3D-G/PANI were studied.It was found that when An was 0.08m L,the electrochemical performance of 3D-G/PANI obtained by in-situ growth of nano-PANI on the 3D-G skeleton was optimal.SEM and TEM morphology characterization showed that PANI grew on 3D-G in the form of nanoparticles.The specific capacitance of 3D-G/PANI electrode material at a current density of1.5m A/cm² is 542F/g.After 1000 cycles,the specific capacitance remains 85%at a current density of 10m A/cm².（2）Three-dimensional aminated graphene（3D-GN）was prepared by amination of partially reduced 3D-G with p-phenylenediamine（PPD）as functionalized molecule,and three-dimensional aminated graphene/polyaniline（3D-GN/PANI）was prepared by in-situ polymerization.By studying the electrochemical properties of 3D-GN/PANI with the dosage of An and the molar ratio of An to APS.The results show that when the dosage of An is 100μL and the molar ratio of An to APS is 2:1,the electrochemical performance of 3D-GN/PANI obtained by in situ growth of nano PANI on the 3D-GN framework is optimal.SEM and TEM morphology characterization showed that PANI grew vertically on 3D-GN in spike shape.The specific capacitance of 3D-GN/PANI was 578 and 489F/g at a current density of 1.5and 20m A/cm² current densities.After 3000 cycles,the capacitance retention rates are92%at a current density of 10m A/cm².（3）Three-dimensional sulfonated graphene（3 D-GS）was synthesized by one-step hydrothermal reduction with hydrazine hydrate（N₂H₄×H₂O）as reducing agent and diazo salt of p-aminobenzene sulfonate as functional molecule.Three-dimensional sulfonated graphene/polyaniline（3D-G/PANI）composite electrode material was prepared by in-situ polymerization.The effect of the dosage of diazo salt and An on the electrochemical performance of 3D-GS/PANI was studied.It was found that when the mass of the diazonium salt of P-aminobenzene sulfonic acid diazo salt was 30mg and the amount of An was 100μL.The electrochemical performance of 3D-GS/PANI obtained by in situ growth of nano PANI on the 3D-GS framework was optimal.SEM and TEM morphology characterization showed that PANI grew uniformly on 3D-GS in the form of nanoparticles.The specific capaci tance of 3D-GS/PANI is 639F/g at a current density of 1.5m A/cm².After 3000 cycles,the capacitance retention rate is 91%at a current density of 10m A/cm².