仿生石墨烯复合材料的制备及其电化学性能

Preparation and Electrochemical Properties of Bionic Graphene Composites

石墨烯作为一种理想的新型二维纳米材料,有着独特的理化性能和广泛应用价值,但成本高、产率低、分散性较差是制约其推广应用的关键。为了解决这一问题,现以北方杨树叶为原料,以KMn O4和H2SO4为氧化剂,水热氧化裂化直接得到Mn O2仿生石墨烯复合材料(Mn O2@BGO)。通过XPS、SEM、TEM、XRD等测试手段对材料组成及微观结构进行表征。从SEM、TEM及氮气吸附脱附分析可以看出,通过氧化碳化直接得到的Mn O2@BGO复合材料,Mn O2分布均匀,比表面积达605 m2/g。此复合材料与未经氧化剂浸渍得到碳材料(BGO)相比,更多的保留了叶片原有的叶脉结构和孔隙,孔径分布较窄,平均孔径为3. 7 nm。从AMF分析可以看出,Mn O2@BGO复合材料类似二维纳米膜,得到的片层厚度最薄<1. 23 nm,最厚≯5. 65 nm,平均厚度2. 57 nm。XPS分析表明,C存在形式以C=C为主,表明材料石墨化程度较高,属于仿生石墨烯。电化学性能分析表明,在电流密度在1 A/g时,该材料所做电极比电容为387 F/g。

Graphene has a typical two-dimensional nanostructure and is used in a wide range base on the unique physical and chemical properties.However,high cost,low yield and poor dispersion are the key factors restricting its application.In this study,MnO 2 biomimetic graphene composites(MnO 2@BGO)were obtained directly using KMnO 4 and H 2SO 4 as oxidants and north poplar leaves as raw materials by hydrothermal oxidation cracking.The composition and microstructure were characterized by XPS,SEM,TEM,XRD and so on.MnO 2 is uniformly dispersed on the surface of MnO 2@BGO with a specific surface area of 605 m 2·g-1 by SEM,TEM and N 2-adsorption desorption.Compared with carbon material(BGO)impregnation without oxidant,MnO 2@BGO retained more original vein and pores of the leaves,with narrow pore diameter distribution and an average pore diameter of 3.7 nm.AMF images of MnO 2@BGO present constructure of two-dimensional nano film with the thickness of the thinnest<1.23 nm and the thickest≯5.65 nm.Average thickness 2.57 nm.XPS analysis show that the existence form of C was mainly C=C,indicating that the material was highly graphitized and belonged to bionic graphene.The electrochemical analysis shows that the electrode specific capacitance of the material is 387 F/g when the current density is 1 A/g.