In situ synthesis of super-long Cu nanowires inside carbon nanotubes with coal as carbon source

摘要

Nano-sized copper wires have received considerable attention because of their potential applications in next generation electronic nanodevices in future 1,2. Up to now, a number of approaches including vapor depositions 1, template synthesis 2,3, solution-phase reactions 4,5 and vapor-solid reaction growth (VSRG) 6 have been developed for making copper nanowires. Despite of the great progresses, some tough problems related to the quality of copper nanowires such as poor oxidation resistance and crystallinity, short length, and nonlinear morphology still need to be addressed 1-7. Carbon nanotubes (CNTs) are believed to be a good template for making Cu nanowires with perfect 1D morphology and good stability, and this idea has been tested by arc discharge in hydrogen 8 or microwave plasma-assisted CVD 9. Here, we report a simple arc-discharge method for in situ synthesis of Cu-filled CNTs with coal as carbon precursor. It has been found that super-long crystalline Cu nanowires, of which the average length is over several tens of micrometers and the aspect ratio is ca. 200-360, can be directly fabricated inside the CNTs in large quantity.