Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, C.U. San Manuel., C. P. 72570, Puebla, Mexico.
J Mol Model. 2013 Jan;19(1):321-8. doi: 10.1007/s00894-012-1539-4. Epub 2012 Aug 15.
In this paper first principles total energy calculations to study the adsorption of amine group (NH2) on graphene (G) and boron nitride (hBN) nanosheets are developed; the density functional theory, within the local density approximation and Perdew-Wang functional was employed. The sheets were modeled with a sufficiently proved CnHm-like cluster with armchair edge. The optimized geometry was obtained following the minimum energy criterion, searching on four positions for each nanosheet: perpendicular to the carbon atom, on the hexagon, inside the hexagon and on the bridge C-C, for the G-amine interaction; and, perpendicular to the B, perpendicular to the N, on the hexagon, and inside the hexagon, for the hBN-amine interaction. A physisorption, with amine parallel to the C-C-C bond with a distance graphene-amine of 2.56 Å, was found. For the case of BN a B-N bond, with bond length equal to 1.56 Å, was found; the amine lies perpendicular to the nanosheet. When the graphene is doped with B and Al atoms a chemisorption with B-N (1.57 Å) and Al-N (1.78 Å) bonds is observed; the bond angle in the amine group is also incremented, 5.5° and 8.1°, respectively. In the presence of point defects (monovacancies) of B in the hBN-amine and C in the G-amine, there exists chemisorption, increasing the reactivity of the sheets.
本文采用基于密度泛函理论的第一性原理总能量计算方法，研究了氨基（NH2）在石墨烯（G）和氮化硼（hBN）纳米片上的吸附；采用局域密度近似和 Perdew-Wang 泛函。纳米片采用经过充分验证的 CnHm 样簇和扶手椅边缘进行建模。根据最小能量准则，在每个纳米片的四个位置上搜索，得到优化的几何形状：对于 G-胺相互作用，垂直于碳原子、在六边形上、在六边形内和在 C-C 桥上；对于 hBN-胺相互作用，垂直于 B、垂直于 N、在六边形上和在六边形内。发现氨基与 C-C-C 键平行，距离石墨烯-胺为 2.56 Å，为物理吸附。对于 BN，发现 B-N 键，键长等于 1.56 Å，胺垂直于纳米片。当石墨烯掺杂 B 和 Al 原子时，观察到 B-N（1.57 Å）和 Al-N（1.78 Å）键的化学吸附；胺基的键角也分别增加了 5.5°和 8.1°。在 hBN-胺中的 B 点缺陷（单空位）和 G-胺中的 C 点缺陷存在时，存在化学吸附，增加了纳米片的反应活性。
