Chemistry Reference
In-Depth Information
Fig. 1 The most stable optimized structures of Au, Ag, and Pt on the pristine, B-,
N-CNTs.
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showed there was little or no overlap between PDOS of Au (Ag) and car-
bon. The charge density difference analysis revealed that the covalent
bond formed between Pt (Au) and two (one) carbon, whereas there was a
lack of bond interaction between Ag and CNTs. In contrast, the influence
of B-, N-doping on the metal binding on CNTs strongly depends on the
specific metal monomer, as shown in Fig. 1. For Au and Ag systems, the
B-, N-doping both significantly enhances the adhesion of these mono-
mers on CNTs because of the enhanced binding energies. The PDOS of
Au and Ag on B-, N-CNTs also demonstated more dispersed, more
bonding and anti-bonding states than that on pristine CNTs. In addition,
the adhesion ability of Au and Ag was stronger on B-CNTs than that on N-
CNTs because of direct B-Au, B-Ag interactions, resulting in electron
redistribution. The major character of the bonding between Au and
carbon on pristine CNTs and N-CNTs was covalent. But the electron rich
N-CNTs further enhanced the covalent bond than that on pristine CNTs.
Ag was very similar to Au. The major difference was that Ag had no any
bond interaction with pristine CNTs. On B, N-CNTs, the ionic and co-
valent bond formed between Ag-B and Ag-C. Obviously, the covalent
bond between Ag and carbon on N-CNTs can be formed due to electron
