氧化裂化合成生物质碳材料及其电化学性能研究

生物质碳材料具有成本低、来源广泛、孔隙率可调可控、形貌多样、易生产、易掺入杂原子等优点,因此,生物质碳基材料的开发和应用成为现代材料科学一个非常重要的领域。将植物叶片用不同氧化剂进行水热氧化处理,600℃碳化得到生物质碳材料。水热氧化处理工艺与传统热裂解工艺相比,降低了裂解温度,极大程度保持了叶片脉络结构,得到类石墨烯的薄层碳化材料。样品通过XRD、XPS、TEM、SEM等进行表征。结果表明,用不同氧化剂水热氧化所得到的碳材料元素组成和微观结构差别较大。当氧化剂为高锰酸钾时,所得到的生物质碳材料(MnOC)既保留了叶片原有的微观孔道,又形成了新的孔隙,比表面积可达482.934 m^2/g,平均孔径为3.833 nm。从XPS、XRD分析可以看出,MnOC样品石墨化程度相对较高,并最大程度保留了N元素(原子百分比为6.5%)。TEM、AFM图像分析表明,MnOC样品呈片层结构,厚度不足2 nm,将其制备成电极片,在电流密度为1 A/g时,比电容可达191.15 F/g。

Synthesis of biomass carbon materials by oxidativecracking and their electrochemical performance

Biomass carbon materials have the advantages of low cost,wide source,adjustable and controllable porosity,diverse morphology,easy production,and easy to incorporate heteroatoms.Therefore,the development and application of biomass carbon-based materials have become a very important area in modern materials science.In this work,the plant leaves were treated by hydrothermal oxidation with different oxidants.Then the obtained product was pyrolyzed at 600℃to obtain biomass carbon materials.Compared with the traditional pyrolysis methods,hydrothermal oxygen reaction could reduce the pyrolysis temperature and maintain the vein structure of leaves to a great extent.Graphene like thin-layer carbonization materials were obtained.The samples were characterized by XRD,XPS,TEM and SEM.The results show that the properties of the carbon materials obtained by hydrothermal oxidation with different oxidants were different.When the oxidant was KMnO4,the obtained biomass carbon material(MnOC)retained the original microscopic pores of the blade and formed new pores.Its specific surface area could reach 482.934 m^2/g with an average pore size of 3.833 nm.XRD and XPS results show that the degree of graphitization of MnOC was relatively high and preserved the N element(6.5%)as much as possible.TEM and AFM analysis shows that MnOC had a lamellar structure with the thickness of less than 2 nm.The MnOC exhibited the capacitance of 191.15 F/g at 1 A/g.