Boron Atoms as Loop Accelerator and Surface Stabilizer in Platelet‐Type Carbon Nanofibers

Graphitic nanomaterials from biogas-derived carbon nanofibers

“…The development of a more graphite-like structure is associated with the increase of the G-band (after graphite) and the decrease of the D-band (after defects) intensities of the Raman spectrum [23], therefore a decrease of this ratio was expected to occur. The formation of loops between adjacent active edge planes on the graphene layers of the BCNFs during HTT could account for the gap in the evolution of the I D /I t ratio with increasing structural order, as assessed by XRD, since loops are known to contribute to the D' band intensity [36], which in carbons has been ascribed to edge planes [26].…”

Important roles of graphene edges in carbon-based energy storage devices

“…Here, boron atoms (B) was suggested as a surface modifier of carbon nanofibers [49] because of its high ability to substitute into the hexagonal carbon network [50,51]. Thus, catalytically grown platelet-type carbon nanofibers were selected as a starting material [37] since relatively crystalline graphene layers are stacked regularly along the length direction of the carbon nanofiber, and the accessible surface area is covered with active edges.…”

“…In order to evaluate the effectiveness of B as a stabilizing agent for open edges (dangling bonds), carbon nanofibers were thermally treated in the presence of elemental B at various temperatures using a graphite furnace. Carbon nanofibers are in the form of short rods (Figure 6a) and have semi-rectangular cross-sectional morphology (inset in Figure 6a) [49]. Moreover, relatively crystalline graphene layers are stacked regularly along the length direction of the carbon nanofiber (Figure 6b) [49], the accessible surface area of which is fully covered with chemically active end planes.…”

“…Carbon nanofibers are in the form of short rods (Figure 6a) and have semi-rectangular cross-sectional morphology (inset in Figure 6a) [49]. Moreover, relatively crystalline graphene layers are stacked regularly along the length direction of the carbon nanofiber (Figure 6b) [49], the accessible surface area of which is fully covered with chemically active end planes. When an undoped sample was thermally treated in argon at 2200 and 2500 • C, the active edges were structurally converted to energetically stable multi-loops (Figure 6c and 6d) [49].…”

“…Moreover, relatively crystalline graphene layers are stacked regularly along the length direction of the carbon nanofiber (Figure 6b) [49], the accessible surface area of which is fully covered with chemically active end planes. When an undoped sample was thermally treated in argon at 2200 and 2500 • C, the active edges were structurally converted to energetically stable multi-loops (Figure 6c and 6d) [49]. For the undoped sample, multiloop formation was not observed at 1900 • C. In contrast, we clearly observed formation of multi-loops in a B-doped sample treated at 1900 • C (Figure 6e).…”