碳包覆铜纳米颗粒的比表面积和孔结构

摘要

采用直流电弧放电等离子体技术制备碳包覆铜纳米颗粒,并对样品的形貌、晶体结构、粒度、比表面积和孔结构采用高分辨透射电子显微镜(HRTEM)、X 射线衍射仪(XRD)和 N2吸-脱附等测试手段进行分析.结果表明:直流电弧等离子体技术制备的碳包覆铜纳米颗粒具有典型的核壳型结构,内核为面心立方的金属铜,外壳为石墨碳层.颗粒主要呈球形或椭球形,粒度相对比较均匀,分散性良好,粒径分布在20~100 nm范围内,平均粒径为50 nm,外壳碳层的厚度为10 nm.碳包覆铜纳米颗粒的等温吸附曲线属Ⅳ型,晶粒之间的孔隙以介孔为主,样品的BET比表面积为33 m2/g,当量粒径为45 nm,与TEM和XRD测得的结果基本一致.BJH吸附累积总孔孔容与BJH吸附平均孔径分别为0.112 cm3/g和13 nm.%Carbon encapsulated Cu nanoparticles were successfully prepared by DC arc discharging plasma technology. The product was characterized by X-ray diffractometry (XRD), high resolution transmission electron microscopy (HRTEM) and low-temperature N2 adsorption desorption to determine the morphology, crystal structure, particle size, specific area and pore structure. The results indicate that the carbon encapsulated copper nanoparticles have typical core shell structure, the core is metal face centered cubic structure copper, and the outer shell is graphite carbon layer. The particles morphology mainly exhibit spherical or ellipsoidal shapes with relatively uniform particle size and good dispersion. The particle size distribution is in the range of 20?100 nm, the average particle size is 50 nm, and the thickness of the shell carbon layer is about 10 nm. The N2 adsorption and desorption isotherm belongs to type Ⅳ, most of pores between grains are mesoporous pore, the BET specific surface area is 33 m2/g, and the equivalent particle size is 45 nm, which is consistent with the results measured by TEM and XRD. The BJH adsorption cumulative pore volume and adsorption average pore size are 0.112 cm3/g and 13 nm, respectively.