Electronic Structure of a Polybenzimidazole-Wrapped Single-Wall Carbon Nanotube

Polymer wrapping on a carbon nanotube (CNT) surface by polybenzimidazoles (PBIs) allows us to immobilize platinum nanoparticles on pristine CNTs and to use it as the electrocatalyst of polymer electrolyte membrane fuel cells (PEMFCs), thereby improving the durability of PEMFCs. In this work, for the first time, we present the fundamental insights into the electronic structure and the interaction present in the single-wall CNT (SWCNT) and PBI composite through comprehensive theoretical study supported by experiments. Our analyses predict that PBI possesses stable helical wrapping around SWCNT because of the strong noncovalent π-π interaction between them, in which PBI participates more than SWCNTs. It is also found that the functionalization of SWCNTs by PBI is independent of the SWCNT chiralities and that the functionalization does not affect the intrinsic properties of SWCNTs, making the SWCNT/PBI-based membrane electrode assembly a good candidate for high-performance PEMFCs.