| AVS 66th International Symposium & Exhibition | |
| 2D Materials | Thursday Sessions |
| Session 2D+AS+BI+HC+MN+NS+PS+SS+TL-ThA |
| Session: | Surface Chemistry, Functionalization, Bio, Energy and Sensor Applications |
| Presenter: | Zahra Hooshmand, University of Central Florida |
| Authors: | Z. Hooshmand, University of Central Florida P. Evans, University of Nebraska - Lincoln P.A. Dowben, University of Nebraska - Lincoln T.S. Rahman, University of Central Florida |
| Correspondent: | Click to Email |
In a joint experimental and theoretical study, we have uncovered evidence of the importance of symmetry in the adsorption of the isomers of diiodobenzene on MoS2(0001). The intensity ratio of iodine to molybdenum measured, as a function of exposure for different isomers of the diiodobenzene, show that while for ortho (1,2-) and para (1,4-) diiodobenzene the rate of adsorption at 100 K is very low, that for meta (1,3-) diiodobenzene is considerably more facile. We have applied dispersion corrected density functional theory-based calculations to understand the subtleties in the electronic structure and geometry of adsorption of these diiodobenzene isomers on MoS2(0001). All three isomers are found to weakly chemisorb with the same binding strength as well as adopt similar configurations. The calculated electron affinity of the three molecules also do not show a specific trend that would verify experimental data. However, analysis of the frontier orbitals indicate that those of 1,3-diiodobenzene are strongly affected by interactions with MoS2, while that of the other two isomers remain unchanged. Our results show that symmetry is the identifying factor in these adsorption characteristics. The results of frontier orbitals analysis confirm that for adsorption of (1,2-) and (1,4-) diiodobenzene a reduction in the symmetry of the adsorbent is needed. To further validate our conclusions, we compare the above results with that of the adsorption of the diiodobenzene isomers on defect-laden MoS2(0001).
* Work support in part by DOE grant DE-FG02-07ER15842