A DFT study on doping assisted changing of B₈₀ electronic structure: Promising candidates for NH₃ sensor

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• 作者：Aidin Bahrami ; Sirous Yourdkhani ; Mehdi D. Esrafili ; Nasser L. Hadipour
• 关键词：B80 buckyball ; Doping ; Adsorption ; NH3 ; DFT ; AIM
• 刊名：Sensors and Actuators B: Chemical
• 出版年：February, 2014
• 年：2014
• 卷：191
• 期：Complete
• 页码：457-463
• 全文大小：1576 K

文摘

Density functional theory calculations at the B3LYP with 6-31G(d), 6-311 + +G(d,p), and LANL2DZ basis sets were carried out to investigate the adsorption of NH₃ on the series of B₇₉X structures with X = {B, Al, Ga, N, F}. In order to go further and gain insight into the binding features of doped B₈₀ complexes with NH₃, the structural and electronic parameters as well as the Atoms in Molecules (AIM) properties were examined. The parameters and the obtained results by AIM were regarded as powerful tools to reveal some unknown aspects of electronic structures of the boron buckyballs upon the adsorption when they were exposed to doping. According to our results, the interaction of NH₃ with the external wall of pristine and doped B₈₀ leads to the remarkable differences in their structures and conductivities. The results show that B₇₉X with X = {B, Al, Ga} kept their original structure greatly while the structure of B₇₉X with non-metal dopants, particularly fluorine, were changed dramatically. For instance, when F was substituted as a dopant on cap site, the F atom was projected inside the buckyball. It is clarified that B₇₉Al, B₇₉Ga and B₇₉F complexes gain noticeable response to NH₃ by locating the dopants in the cap site. Therefore, it is concluded that they can potentially regard as NH₃ sensors. In addition, AIM based analyses indicated a partial covalent nature for all the complexes except NH₃-B₈₀ and frame-NH₃-B₇₉F. Moreover, it was found that the covalent nature of the NX bonds is decreased by increasing of metallic characteristic of X atom.