Preparation Uniform Thin Tubular Carbon Nanofiber Using Novel Bimetallic Catalyst at Low Temperature and Its Structural Feature

Uniform thin tubular carbon nanofibers (TCNFs), composed of two nanofibrils ca. 20 nm in diameter and with relatively high graphitic property, were prepared using a chemical deposition method from a CO/H₂ gas mix (1:4 v/v) over a novel bimetallic (Fe-Mn, 3:7 w/w) catalyst at a low temperature of 500-540 °C. Mn effectively activated the Fe catalyst when preparing selective thin TCNFs. The specific amount of Mn 70 wt % on the Fe-Mn catalyst was key for the selective preparation of uniform duplicated CNFs with an aligned tubular graphene structure. The obtained TCNFs had relatively high graphitic property; the interlayer spacing (<i>d</i> ₀₀₂) and the stacking height Lc(002) were <0.3420 and >5.4 nm, respectively, because of the unique duplicated morphology.