AVS 54th International Symposium | |
Nanometer-scale Science and Technology | Tuesday Sessions |
Session NS+MS-TuA |
Session: | Characterization of Nanostructures |
Presenter: | C.-L. Sun, Academia Sinica, Taiwan |
Authors: | C.-L. Sun, Academia Sinica, Taiwan H.-W. Wang, National Taiwan University M. Hayashi, National Taiwan University L.-C. Chen, National Taiwan University K.-H. Chen, Academia Sinica, Taiwan |
Correspondent: | Click to Email |
We present the N-doping induced atomic-scale structural deformation in N-doped carbon nanotubes (CNTs) by using energy-filtered transmission electron microscopy (EFTEM) and density functional theory calculations. EFTEM N mapping image shows that N is indeed incorporated in the bamboo-like CNTs with non-uniform distribution. The interlinked parts in CNTs are brighter than the sidewall, indicating that they contain higher N concentration. We then construct the finite cluster models for CNTs with pure and two doping types in order to study the detailed structural changes in atomic scale. For substitutional-N-doped nanotube clusters, the N dopant with an excess electron lone pair exhibits the high negative charge and the homogeneously-distributed dopants enlarge the tube diameter in both zigzag and armchair cases. On the other hand, in pyridine-like-N-doped ones, the concentrated N atoms result in positively curved graphene layer and thus can be responsible for tube wall roughness and the formation of interlinked structures. Several examples for its relevant applications in energy conversion and storage will be briefly introduced in the end.