Xuehua Wang

Preparation and Mechanism of Carbon Encapsulated Cu Nanoparticles

In recent years, research interests in copper nanoparticles have been increased significantly due to their excellent performance in tribology, catalysis and many other fields. However, their applications have been still limited because the bare nanoparticles are easily oxidized. Therefore, the study of copper nanoparticles encapsulated in carbonaceous shells is an important issue. In this study, the carbon encapsulated copper nanoparticles were prepared using copper nitrate as the metal sources and using sucrose as the carbon sources, through reducing and annealing. The phase, morphology, particle size and structure of as-prepared samples were characterized using X-ray diffraction, field emission transmission electron microscopy, scanning electron microscopy and Raman spectroscopy, respectively. The results indicate that the samples exhibit well core/shell structure, with sphere form and uniform size (50 nm in average). The copper cores consists of polycrystalline particles with fcc structure, whose size varies from 20 nm to 60 nm. The shell is amorphous carbon and its thickness is about 10 nm. In addition, the formation mechanism of carbon encapsulated copper nanoparticles was discussed and presented in the paper.