Efficient carbon nanotube sponges production boosted by acetone in CVD-Synthesis

Abstract

"A high production of nitrogen-doped carbon nanotube sponges (N-CNS) was obtained at 1020 °C with 4 h of growth in an aerosol-assisted chemical vapor deposition (AACVD) experiment modified with two independent sprayers feeding the reactor. Sprayer-1 contained a solution made of benzylamine, ferrocene, and thiophene; sprayer-2 contained a solution made of ethanol-acetone, ferrocene, and thiophene. N-CNS were produced with three different acetone concentrations and collected along the reactor. The N-CNS were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The main trends that were found when adding acetone as a precursor are: (1) an increase of the carbon fiber diameters; (2) favored the formation of Fe3C nanoparticles that were encrusted into the outermost layers of the carbon fibers; (3) a reduction of the oxidation temperature; and (4) a decrease in the oxygen content. The nitrogen concentration in N-CNS was approximately 3% w/w and is exhibited in mainly pyrrolic, pyridinic, and quaternary fashions. The N-CNS showed super hydrophobic and oleophilic properties. The absorption capacities were tested for various organic solvents."