Synthesis And Investigation Of Graphene-based Hybrid Material For Supercapacitor

Supercapacitor,as one of the most promising green energy devices,has drawn great attention in the future communication and transportation devices recently due to the ultrahigh power density,excellent cycle stability,and so on.Although graphene has been playing a dominant role in the supercapacitor electrode materials,its commercialization has been hindered by some drawbacks such as the agglomeration and zero band gap.In this work,we modified graphene through a series of doping methods aimed to improve the specific capacitance and some other properties of graphene electrode materials.And electrochemical tests indicated that the hybrid materials showed a good specific capacity property,high rate capability and much better cycling stability,which are matched with current superior works,even better than some of them.The works could divide into three parts:(1)Graphene oxide was synthesized by the modified Hummers method.SEM,TEM of GO with high transparence displays gauze-like and wrinkled morphology.XRD of GO shows a sharp and single diffraction peak at 2? = 11.7o with good crystalline.Weak raman peaks indicates GO has more defects and disorder increases.IR exhibits the graphite has been oxidized successfully with some oxygen-groups on it.(2)A three dimensional N-doped graphene/CNTs/AC(NGCA)composite has been fabricated using above GO as the precursors and CNTs,AC and melamine as the mediator.SEM,TEM,XPS,BET results indicate disordered NG nanosheets were uniformly decorated with CNTs and AC,forming a sandwich structure with hierarchal mesopores,large surface area and high conductive network.It presents the excellent electrochemical performances as a supercapacitor electrode material such as ultrahigh specific capacitance,good cycle stability.(3)NG/MoS2 hybrid has been synthesized using above GO as the precursor and sodium molybdate and sulfourea as the Mo and S sources,respectively.SEM,TEM,XPS and BET results indicate MoS2 have doped into NGM with loose and porous structure.And electrochemical test showed NGCA has good specific capacitance,excellent cycle stability and so on.