Assembling perylene molecules in between an ordered array of Pd nanoparticles
Résumé
Ordering hybrid assemblies of NPs with organic molecules gives the opportunity to explore a new promising approach to control and study fundamental processes involved in NP-molecule coupling, including charge transfer. High quality ultrathin Al2O3 layers on Ni3Al(111) enables to grow high density narrow size distributed nanoparticles (NPs) [1], particularly well adapted to study small cluster reactivity for heterogeneous catalysis [2] and molecule-NP interactions to follow charge transfer in individual molecule for molecular electronics [3].
Here, we combine multiscale investigation tools such as vibrational sum frequency generation and UV/Vis absorption spectroscopies with STM microscopy. It allows us understanding growth mechanism [1] and geometry of Pd NPs [2], molecular adsorption or the growth of dense molecular monolayer and evidence their coupling with NPs [2,3]. NP growth can be followed in realtime layer-by-layer from a few atoms to several hundred atoms [2]. The nanoscale ordering of a hybrid assembly of Pd NPs with perylene molecules was demonstrated. The ordering, driven by the alumina template, was achieved for ~1 nm NPs and flat-lying molecules with a perylene:NP coverage ratio of two. This opens avenues to build more complex systems were molecules bridge NPs in a long-range ordered hybrid network.
[1] N. Alyabyeva, A. Ouvrard, A.-M. Zakaria, F. Charra, B. Bourguignon „Transition from disordered to long-range ordered nanoparticles on Al2O3/Ni3Al(111)“ Appl. Surf. Sci. 2018, 444, 423-429.
[2] N. Alyabyeva, A. Ouvrard, A.-M. Zakaria, B. Bourguignon „Probing Nanoparticle Geometry down to Subnanometer Size: The Benefits of Vibrational Spectroscopy“ J. Phys. Chem. Lett. 2019, 10, 624-629.
[3] N. Alyabyeva, A. Ouvrard, R. Lazzari, B. Bourguignon „Ordered Hybrid Assembly of Palladium Nanoparticles and Perylene Molecules on an Alumina Template“ J. Phys. Chem. C 2019, 123, 19175-19182.