A method is presented for the deposition of gold clusters onto reduced graphene oxide, without aggregation of the gold clusters.

A simple, low-cost method of preparing photocatalytic TiO2 thin films using RF plasma has been developed, offering known elemental composition, homogenous depositions, and easily modifiable crystallinity and surface properties.

A loss of Ru–CO sites on the clusters suggests encapsulation.

Metal clusters typically consist of two to a few hundred atoms and have unique properties that change with the type and number of atoms that form the cluster. Metal clusters can be generated with a precise number of atoms, and therefore have specific size, shape, and electronic structures. When metal clusters are deposited onto a substrate, their shape and electronic structure depend on the interaction with the substrate surface and thus depend on the properties of both the clusters and those of the substrate. Deposited metal clusters have discrete, individual electron energy levels that differ from the electron energy levels in the constituting individual atoms, isolated clusters, and the respective bulk material. The properties of clusters with a focus on Au and Ru, the methods to generate metal clusters, and the methods of deposition of clusters onto substrate surfaces are covered. The properties of cluster‐modified surfaces are important for their application. The main application covered here is catalysis, and the methods for characterization of the cluster‐modified surfaces are described.

In this study Ru3 clusters are deposited onto radio frequency-sputter deposited TiO2 (RF-TiO2) substrates by both solution submersion and chemical vapor deposition (CVD) of Ru3(CO)12, as well as cluster source depositions of bare Ru3. TiO2(100) and SiO2 are used as comparison surfaces with differing cluster-surface interactions. Temperature-dependent X-ray photoelectron spectroscopy (XPS), angle-resolved XPS, and temperature-dependent low energy ion scattering (TD-LEIS) are used to probe how the cluster-surface interaction changes due to heat treatment. Results show that bare Ru3 supported on SiO2 remain on the surface layer but agglomerates upon heating. Conversely, when supported on sputter-treated RF-TiO2, bare Ru3 is encapsulated by a layer of titania substrate material as-deposited. Ligated Ru3(CO)12 is also covered by a layer of titania when deposited onto sputter-treated RF-TiO2 but heat treatment is required to remove most of the ligands. TD-LEIS is used to directly measure the encapsulation of CVD Ru3(CO)12 clusters on sputter-treated RF-TiO2 and determine the substrate overlayer thickness. The overlayer was found to be 1-2 monolayers, which is thin enough for catalytic or photocatalytic reactions to occur without Ru being present in the outermost layer.