Growth of carbon nanofibers catalyzed by silica-coated copper nanoparticles

Silica-coated copper nanoparticles were synthesized by coating copper nanoparticles with a silica shell through microemulsion. The copper nanoparticles are 30–40 nm in diameter and the silica coating is 10 nm in thickness. After coating, copper nanoparticles were encapsulated in a silica matrix. These particles were used as a catalyst for the growth of carbon nanofibers in a tubular furnace. It is found that carbon nanofibers are mirror-symmetric growth and 100 nm in diameter. During growth, the copper nanoparticles moved out of the silica. As the experiment progressed, the interplanar spacing of copper (2 2 0) increased from 0.1288 nm to 0.1306 nm indicating that (2 2 0) plane exhibited high catalytic activity. The out-of-sync growth of different faces provides new evidence for the research of growth mode in carbon nanofibers.

Silica-coated copper nanoparticles are used as catalyst. During chemicl vapor deposition, carbon nanofibers grow over the copper nanoparticles which move out of the silica coating. The interplanar spacing of copper (2 2 0) increased from 0.1288 nm to 0.1306 nm indicating that (2 2 0) plane exhibited high catalytic activity.Figure optionsDownload as PowerPoint slideHighlights
► Silica-coated copper nanoparticles were used as catalyst for carbon nanofibers.
► Silica coating is used as a barrier to discover the selective catalysis of copper.
► Copper nanoparticles could move out of the silica to catalyze carbon nanofibers.
► Higher activity would promote a preferential catalytic reaction.
► Copper (2 2 0) move out of the silica shell and participate in catalysis firstly.