生物质纳米碳膜的制备及其电化学性能

Preparation and electrochemical performance of biomass nano carbon film by hydrothermal oxidation

将衰老叶片用H_(2)SO_(4)进行水热氧化得到氧化水合碳前驱体,前驱体经烘干研磨在KOH存在下进行碳化得到生物质纳米碳膜(LS-OCM),通过FT-IR,XRD、TEM、SEM、AFM、XPS及N_(2)吸附-脱附等测试手段对其材料组成和微观形貌进行表征。TEM、SEM及N_(2)吸附-脱附分析显示,制得生物质纳米碳膜材料(LS-OCM)既保留叶片原有的叶脉结构又形成丰富多级的孔道结构,比表面积约为450.7 m^(2)/g,孔径分布较窄,平均孔径为3.8 nm;AFM分析显示,LS-OCM类似二维纳米膜,片层平均厚度在1.6 nm左右;XPS及XRD分析表明,该材料中C主要以C=C形似存在,为类石墨烯碳膜。电化学性能分析表明,在电流密度为0.25 A/g下,LS-OCM比电容为262.58 F/g,循环100圈,比电容仍然可达150.8 F/g,表明材料具有良好的稳定性。

The biomass carbon film(LS-OCM)was obtained by carbonization of the hydrated carbon precursor in the presence of potassium hydroxide.Oxidized hydrated carbon(precursor)was prepared using H_(2)SO_(4) as oxidants and aging leaves as raw materials by hydrothermal process.The composition and microstructure were characterized by Fourier Transform Infrared(FT-IR),X-ray diffraction(XRD),Transmission electron microscope(TEM),Scanning electron microscope(SEM),Atomic force microscope(AFM),X-ray photoelectron spectroscopy(XPS)and N_(2 ) adsorption-desorption.The biomass carbon material(LS-OCM)retains some original microscopic pores of the leaf and forms new rich multistage pores by the TEM,SEM and N_(2 )adsorption-desorption.Its specific surface area reaches 450.7 m^(2)/g,with narrow pore diameter distribution and an average pore size of 3.8 nm.The AFM image shows that LS-OCM presents the two-dimensional nano film constructure with the average thickness of about 1.6nm.XPS and XRD analysis show that the the valence form of carbon of the LS-OCM materal is mainly C=C,which is similar to biomass graphene.The electrochemical performance analysis shows that the specific capacity of LS-OCM is 262.58 F/g at the current density of 0.25 A/g.After 100 cycles,the specific capacity can still reach 150.8 F/g,which shows that the material has good stability.