Investigation of the sorption of gases onto a carbon nanotube with substituted nitrogen atoms-title
Aleksandr D. Grigoriev1, Sergey V. Boroznin1, Irina V. Zaporotskova1. 1Volgograd State University, Volgograd, Russia
Abstract
Substitution of carbon atoms with nitrogen atoms in carbon nanotubes is an effective way to control their physicochemical properties. This mechanism allows to expand the possibilities of their practical application. Nitrogen is a very attractive material for modifying carbon nanotubes. But unfortunately, systematization of studies related to the effect of impurity nitrogen atoms on the properties of carbon nanotubes has not been carried out to date, which weakens the possibility of industrial use of this nanomaterial. Therefore, the purpose of this article is to study the effect of substitution of carbon atoms with nitrogen in CN nanotubes on their sorption properties to CO, Cl₂ and F₂ molecules using quantum chemical modeling methods, analysis of the physicochemical properties of the obtained nanomaterials and forecasting possible areas of their application based on theoretical and real experiments. Pure CNTs have low chemical activity of the surface, limiting gas adsorption and sensory application. However, modification by substituting carbon with nitrogen (C→N) in nanotubes creates active sites, improving the sorption. This changes the electron density, enhancing the interaction with gases. Quantum chemical modeling based on the density functional theory (DFT) allows studying the effect of modification without complex experiments. The DFT method, especially with the B3LYP functional and the 6-31G basis set, accurately predicts the adsorption energies and electronic properties. Data on the sorption of Cl₂ and F₂ on CN nanotubes are limited, especially on the dependence of the adsorption energy on the distance to the surface. The obtained results convincingly demonstrate the high efficiency of the substitution of boron atoms with nitrogen as a modification strategy for significantly increasing the sorption activity of CN(6,0) carbon nanotubes, especially with respect to carbon monoxide (CO).
Speaker
Aleksandr D. Grigoriev
Volgograd State University
Russia
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