超临界CO_2辅助制备Fe_2O_3/石墨烯纳米复合材料及其在超级电容器方面的应用

Fabrication of Fe_2O_3/graphene nanocomposites assisted by supercritical CO_2 and their application in supercapacitors

采用超临界CO_2流体辅助分散技术,合成制备了Fe_2O_3/石墨烯复合材料,通过透射电子显微镜(TEM)表征结果可以看出,Fe_2O_3纳米粒子均匀的负载于石墨烯片层之上,利用其与石墨烯的协同效应,改善各自的固有缺点,增强材料的性能。X-射线能谱(XPS)和X-射线衍射(XRD)结果表明Fe_2O_3和石墨烯之间复合较为完好,且石墨烯结构较为完整,能够大大提升复合材料的导电性。将制得的增强Fe_2O_3/石墨烯复合材料用于超级电容器电极材料,通过循环伏安(CV),恒电流充放电(GCD)和交流阻抗(EIS)测试可知,电容器表现出了优异的赝电容性能,在电流密度为1 A/g时,其比电容量可以达到596 F/g,显示了优异的电化学储能性能。

We prepared Fe203/graphene nanocomposites with supercritical CO2 technology. Transmission electron microscopy （TEM） results indicated that ultrafine Fe2O3 nanoparticles are uniformly and firmly decorated on graphene sheets. The synergistic effect between Fe2O3 and graphene nanosheets could remarkably diminish their inherent drawbacks. X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD） results confirm that Fe2O3 and graphene has a relatively intact interaction, moreover, graphene maintained its complete structure, and the conductivity of the composite can be greatly improved. The as-synthesized Fe2O3 nanocomposite was fabricated into an electrode material of hybrid supercapacitor and characterized by cyclic vohammetry （CV）, and galvanostatic charge - discharge （GCD） and electrochemical impedance spectroscopy （EIS）.The nanocomposite exhibits excellent pseudocapacitive propertiesresuhs and the specific capacitance of the composite reached 596 F/g at the current density of 1 A/g.