Session: COMP Poster Session:

Dissociation of nitrogen molecule with plasmon-enhancement from noble metal nanoparticles has been investigated both experimentally and computationally in recent years. Meanwhile, the mechanism of nitrogen dissociation is still not very clear. The localized surface plasmon resonance for noble metal nanoparticles is usually be considered to be a collective sloshing of free surface electrons upon irradiation at a certain frequency. Recent research has already shown that there are two main surface plasmon modes in Ag nanowires, i.e. longitudinal and transverse modes; the longitudinal plasmon excitation shows a more intense resonance peak for linear silver nanowire. In our study, nonadiabatic dynamics are applied to examine the dissociation of a nitrogen molecule coupled with a silver wire. Ehrenfest dynamics give us information about the motion of nuclei during the dynamics process and real-time TDDFT calculations show the electronic transitions and population of electrons over a certain time period. In this work, we find that the activation and dissociation of nitrogen is typically enhanced when increasing the electric field strength. However, the enhancement is not always monotonic with field strength. We also examine the size effect on catalytic properties of silver chain and find that when the length of Ag wire increases, nitrogen would be easier to dissociate at relatively lower field strengths. Our detailed study gives information about selecting field strength and choosing Ag wire chains as a catalyst for N₂dissociation. It also provides more information about mechanisms involved in nitrogen dissociation using surface plasmon resonance of nanoparticles.

Xiaosong Li

University of Washington

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