Surface Chemistry Controlled Deposition on Nanoparticle Substrates

Hybrid nanoparticles have been widely studied because of their ability to synergistically combine or enhance the optoelectronic, magnetic, or catalytic properties of each component. These properties are highly dependent on the size, shape, and surface chemistry of the nanoparticle, in addition to the arrangement of elements within the nanoparticle architecture. A particularly interesting class of hybrid materials involves the combination of plasmonic materials (e.g. gold, silver, copper, as well as doped-semiconductors) with catalytically active metals (e.g. platinum, palladium, and copper). Here, the plasmonic substrate can convert light into hot carriers that can then be transferred to adsorbate molecules and drive chemical reactions. The efficiency of these processes, however, is strongly dependent on the particle architecture (i.e. core@shell, alloyed, or Janus-type particles) of the hybrid material. Therefore, there is a driving force to be able to control the final hybrid nanoparticle architecture. Surface chemistry has been observed to play a role in deposition morphology and offers a more general method for controlling metal deposition on nanoparticle substrates. Here, we study how surface chemistry can be used to manipulate metal deposition on both Au and Cu2-xSe substrates using ligand density on the particle surface and correlate these results to observed deposition morphologies. By controlling both the ligand identity and extent of functionalization on the surface of the nanoparticle, we are able to direct both the location of nucleation sites as well as the number of sites available. We show that the is not only general for the added noble metals (i.e. Au, Pd, and Pt) but also for the nanoparticle substrate, (i.e. Au nanoprisms, Au nanorods, and Cu2-xSe pseudospherical particles)