| 초록 |
Carbon nanotubes (CNTs) have been considered as an excellent hydrogen adsorbent due to its chemical stability, low mass density, and abundant pore volume and so on... Hydrogen uptake of pristine CNTs at room temperature, however, is not comparable to U.S. DOE target, 6.5wt%. So, many researchers have worked on modifications of CNTs in order to enhance hydrogen uptake, although any recognizable achievement yet has been done. So, we thought that the heteroatom-substitution might affect the electronic state of CNTs, then we calculated the hydrogen adsorption behavior on B or N substituted single walled CNTs using density functional theory (DFT) for the verification. It was found that the hydrogen adsorption energy of heteroatom-substituted SWCNT was almost three times greater than that of pristine SWCNT due to its changes of the electronic states. Also, according to the Langmuir adsorption isotherm, the physisorption coverage of heteroatom-substituted SWCNT is increased nearly thirty times as much as the pristine SWCNT does. |
