碳包覆纳米铜粒子的制备及抗氧化性能

Preparation and anti-oxidation properties of carbon-coated copper nanoparticles

以碳粉和铜粉为原料,碳粉和铜粉的质量比分别为4：1、3：2、2：3、1：4时,采用碳弧法制备4种碳包覆纳米铜粒子;采用X射线衍射（XRD）、透射电子显微镜（TEM）、热重分析（TGA）和差示扫描量热法（DSC）对样品的物相结构组成、形貌、尺寸、相组成以及抗氧化性能进行研究;并对影响碳包覆纳米铜粒子粒径以及制备速率的因素进行研究。结果表明：碳包覆纳米铜粒子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;碳包覆铜纳米颗粒的粒径为20~60nm,粒径随着样品电极中的金属铜含量、放电电流、反应气压的增加而增大;随着样品电极中金属铜含量的增加以及放电电流的增大,碳包覆纳米铜粒子的制备速率加快,而反应气压对制备速率没有明显的影响;随着铜含量的增加,内部铜核具有进一步晶化的趋向,铜对外层碳层的石墨化具有催化作用,铜含量越高碳的石墨化程度越明显;外面的碳层能有效阻止内核的纳米铜粒子的氧化,碳包覆纳米铜粒子比纯铜粉末表现出更好的抗氧化性能。

Four different kinds of carbon-coated copper nanoparticles were synthesized by carbon arc discharge method using powder mixtures containing copper and graphite with mass ratios of graphite to copper of 4：1,3：2,2：3,1：4,respectively.The structures,topographies,size distributions,phase compositions and anti-oxidation properties of those nanoparticles were characterized by X-ray diffratometry（XRD）,transmission electron microscopy（TEM）,thermogravimetric analysis（TGA） and differential scanning calorimety（DSC）,respectively.And the factors influencing the particles size and the yield of carbon coated copper nanoparticles were also discussed.The results indicate that the carbon-coated copper nanoparticles show clear core-shell structure,the cores of the particles are copper,and shells of the particles are graphite carbon layers.The sizes of carbon coated copper nanoparticles are 20？60 nm,and the sizes of nanoparticles increase with increasing the copper content in sample electrode,meanwhile,the particles sizes increase accompanying the increase of the discharge current and reaction pressure.The yield of carbon coated-copper nanoparticles increases with the increase of the copper content,while reaction gas pressure has no significant effect on the yield.And with the increase of copper content,the inner copper core has a trend of further crystallization.Copper possesses catalysis to the external carbon layers,and the graphitization degree becomes more obvious as the content of copper increases.The outside graphitic carbon layers effectively prevent unwanted oxidation of the copper inside.The anti-oxidation property of carbon-coated copper nanoparticles is superior to that of the pure copper powder.