Spherical Structures Composed of Multiwalled Carbon Nanotubes: Formation Mechanism and Catalytic Performance

Abstract

Structured catalyst: A new strategy was used to produce carbon nanotube monoliths by a solid-phase process that was well characterized by in situ techniques. The synthesized spherical nanoparticles display extremely high selectivity in the oxidative dehydrogenation (ODH) of ethylbenzene (see scheme)

Nitrogen doped carbon nanotubes with encapsulated ferric carbide as excellent electrocatalyst for oxygen reduction reaction in acid and alkaline media

“…Amorphous carbon dissolves in metal phase and graphitic layers are formed by the carbon-through-metal diffusion [20]. Above 680 C, Fe 2 O 3 is completely transformed into Fe and Fe 3 C, and graphitic layers begin to grow into carbon nanotubes [18,19]. Meanwhile, the hot liquidlike cementite particles axial move in graphitic layers due to the buildup of compressive stress during thickness growth of the graphitic tube wall, and due to increasing surface tensional forces between the core material and the tube [20].…”

Nitrogen-doped graphene microtubes with opened inner voids: Highly efficient metal-free electrocatalysts for alkaline hydrogen evolution reaction

“…A G-band at 1,580 cm -1 and a 2D-band at about 2,680 cm -1 in the Raman spectra ( Fig. S7(a) in the ESM) of N-GMT further confirmed the formation of graphitic carbon [15][16][17][18][19][20][21][30][31][32]. A typical D-band at 1,350 cm -1 resulting from disordered carbon atoms was also observed in the Raman spectra of N-GMT, suggesting the modification of the sp 2 hybridized carbon atoms with heteroatoms, which here are expected to be nitrogen dopants.…”

“…lattice of carbon nanomaterials was often modified by substitutional doping, and the introduction of nitrogen atoms resulted in greatly improved activity for various catalytic reactions. Recently, nitrogen-doped carbon nanotubes (N-CNT) and graphene (NG) have been demonstrated as metal-free electrocatalysts that offer good to excellent HER and oxygen reduction reaction (ORR) activities [11,[15][16][17][18][19][20][21].…”

Synthesis of graphitic carbon spheres for enhanced supercapacitor performance

“…It should be noted that iron particles about 100 nm are observed in the TEM image of GCS-1000 before Fe removal. Therefore, the large void space might be yielded from the removal of iron nanoparticles [17]. HR-TEM image in Fig.…”