Effects of Field Strength and Silver Nanowire Size on Plasmon-Enhanced N2 Dissociation

Dissociation of the nitrogen moleculevia plasmon-enhanced catalysisusing noble metal nanoparticles has been investigated both experimentallyand computationally in recent years. However, the mechanism of plasmon-enhancednitrogen dissociation is still not very clear. In this work, we applytheoretical approaches to examine the dissociation of a nitrogen moleculeon atomically thin Ag- n nanowires (n = 6, 8, 10, 12) and a Ag-19 (+) nanorod.Ehrenfest dynamics provides information about the motion of nucleiduring the dynamics process and real-time TDDFT calculations showthe electronic transitions and population of electrons over the first10 s of fs time scale. The activation and dissociation of nitrogenare typically enhanced when the electric field strength increases.However, the enhancement is not always monotonic with field strength.As the length of the Ag wire increases, nitrogen is typically easierto dissociate and thus requires lower field strengths, even thoughthe plasmon frequency is lower. The Ag-19 (+) nanorodleads to faster dissociation of N-2 than the atomicallythin nanowires. Overall, our detailed study yields insights into themechanisms involved in plasmon-enhanced N-2 dissociation,as well as provides information about factors that can be used toimprove adsorbate activation.