Effect of Acid Treatment on the Functionalization of Surface, Structural and Textural Properties of Carbon Nanotubes Taunit

Abstract

The role of acid treatment of Taunit carbon nanotubes in the formation of oxygen-containing functional groups on its surface as well as morphological and textural properties was studied. Acid treatment was carried out in an HNO3 solution or its mixture with H2SO4 under mild conditions (85 °C/1 h) with subsequent washing with distilled water or without washing. Properties of the initial and oxidized samples were investigated using elemental carbon, hydrogen, nitrogen, oxygen (CHNO) analysis, BET (Brunauer-Emmett-Teller) determination of surface area, X-ray diffraction, Raman and Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, and hydrogen temperature-programmed reduction. Treatment with HNO3 and HNO3/H2SO4 mixture was shown to be efficient for the formation of various oxygen-containing groups on the Taunit surface; therewith, the water washing step also contributed to functionalization of the surface. Depending on the oxidant, acid treatment increased graphite and oxygen content in the samples by a factor of 3‒4.5. Treatment with HNO3 without water washing exerted a weak effect on the graphite structure ordering, the concentration of aliphatic groups was high as compared to other oxidation conditions. Treatment of Taunit with the HNO3/H2SO4 mixture, on the contrary, increased the number of defects in graphite layers and decreased the concentration of aliphatic structures.

Preparation of Carbon Nanotubes with Supported Metal Oxide Nanoparticles: Effect of Metal Precursor on Thermal Decomposition Behavior of the Materials

“…The CNTs were multi-walled nanotubes with an inner diameter 10-20 nm and a specific surface area 180 m 2 /g. Their physicochemical properties were given and discussed in [40].…”

Effect of the Surface Functionalization of Graphene and MWCNT on the Thermodynamic, Mechanical and Electrical Properties of the Graphene/MWCNT-PVDF Nanocomposites

“…A new peak at 2θ = 56° appeared for the modified MWCNT/GNF-PVDF nanocomposites. The broadening of the graphite peak suggests a decrease in the crystallite size of graphite after the oxidation, whereas an increase in the intensity of the graphite peak for the oxidized samples confirms an increase in the graphite component in the samples due to the dissolution of amorphous carbon in acids [ 50 ].…”

The Development of Metal-Carbon Catalysts for Oxidative Desulfurization of Diesel Fractions

“…The average lattice parameter c is equal to ~ 6.81 Å, and the size along the direction perpendicular to graphite layers, ~ 6 nm. The presence of mixed nickel-magnesium oxide and the metallic nickel phase is caused by the synthesis procedure of CNTs used as the support [29].…”

“…Metal-carbon materials M/CNTs (M = Ce, Сu, Mo) were synthesized by incipient wetness impregnation. To this end, Taunit carbon nanotubes (NanoTechCenter Ltd., Tambov, Russia) [28,29] were impregnated with an aqueous solution of the corresponding metal salt (Ce…”