Synthesis of 4 angstrom single-walled carbon nanotubes in catalytic Si-substituted AlPO4-5 molecular sieves

摘要

4 Angstrom single-walled carbon nanotubes (SWCNs) were fabricated using Si-substituted AlPO4-5 (SAPO-5) molecular sieves as the template. In comparison with neutral AlPO4-5, the SAPO-5 framework plays an important role as a catalyst in pyrolyzing the hydrocarbon molecules, owing to the Bonsted acid sites. The first-principles calculation shows the Si decoration to be very favorable to the formation of carbon nanotubes in the SAPO-5 channels. The resulting SWCNs have better quality than those fabricated without Si doping, evidenced by clearer and stronger radial breathing modes in the Raman spectra. (C) 2004 American Institute of Physics.