Ab Initio Computational Study of Chromate Molecular Anion Adsorption on the Surfaces of Pristine and B- or N-Doped Carbon Nanotubes and Graphene

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• 作者：Yuriy Hizhnyi ; Sergii Nedilko ; Viktor Borysiuk…
• 关键词：Excited states ; CNT ; Graphene ; Chromate ; TD ; DFT ; Binding energy ; Adsorption
• 刊名：Nanoscale Research Letters
• 出版年：2017
• 出版时间：December 2017
• 年：2017
• 卷：12
• 期：1
• 全文大小：1036KB
• 刊物主题：Nanotechnology; Nanotechnology and Microengineering; Nanoscale Science and Technology; Nanochemistry; Molecular Medicine;
• 出版者：Springer US
• ISSN：1556-276X
• 卷排序：12

文摘

Density functional theory (DFT) computations of the electronic structures of undoped, B- and N-doped CNT(3,3), CNT(5,5) carbon nanotubes, and graphene with adsorbed chromate anions CrO₄2− were performed within molecular cluster approach. Relaxed geometries, binding energies, charge differences of the adsorbed CrO₄2− anions, and electronic wave function contour plots were calculated using B3LYP hybrid exchange-correlation functional. Oscillator strengths of electronic transitions of CrO₄2− anions adsorbed on the surfaces of studied carbon nanostructures were calculated by the TD-DFT method. Calculations reveal covalent bonding between the anion and the adsorbents in all studied adsorption configurations. For all studied types of adsorbent structures, doping with N strengthens chemical bonding with CrO₄2− anions, providing a ~2-eV increase in binding energies comparatively to adsorption of the anion on undoped adsorbents. Additional electronic transitions of CrO₄2− anions appear in the orange-green spectral region when the anions are adsorbed on the N-doped low-diameter carbon nanotubes CNT(3,3) and CNT(5,5).