Modular construction of size-selected multiple-core Pt–TiO₂ nanoclusters for electro-catalysis

Abstract

Size-selected binary platinum-titanium dioxide (Pt-TiO2) clusters have been generated using a magnetron sputtering gas condensation cluster source and imaged using a Scanning Transmission Electron Microscope (STEM) in High Angle Annular Dark Field (HAADF) mode. The core-shell clusters exhibit a Pt core of preferred size 30 ± 6 atoms (1 nm), embedded in an oxidised Ti shell, independent of the overall cluster size (varied between 2 nm and 5 nm). Smaller clusters, with mass ≤50 000 Daltons, show a single Pt core while larger clusters, ≥55 000 Daltons, feature multiple Pt cores, either isolated or aggregated within the TiO2 shell. These clusters may have applications in solar hydrogen production; preliminary work indicates catalytic active in the hydrogen evolution reaction.

Exploring the Optical and Morphological Properties of Ag and Ag/TiO2 Nanocomposites Grown by Supersonic Cluster Beam Deposition

“…The grayscale areas have been shown to be composed by a TiO 2 matrix [24] related to the lower Z numbers of the components (Z Ti = 22, Z O = 8). The Ag NPs are partially encapsulated, more similar to the Janus-like than the core-shell configuration [28], the former being commonly observed for bimetallic noble metal nanoparticles [29]. Previous investigations about the structure of the oxide matrix performed by X-ray diffraction [24] suggested that the TiO 2 is amorphous, in agreement with the TEM image shown in Figure 1d, where no sign of regular atomic arrangement can be observed in the “gray” areas.…”

Interaction of nanoparticle properties and X-ray analytical techniques

“…The samples were prepared in the University of Birmingham (BHAM) [10]. The core-shell nanoparticles were produced using a specialized magnetron sputtering technique [32] with 75 % titanium and 25 % platinum by weight in the sputtering target, corresponding to 13 Ti atoms for every Pt atom.…”

“…The commonly used method for the characterization of such "atomic clusters" is the analysis of scanning transmission electron microscope (STEM) images [9]. For the specific Pt-Ti nanoparticle, this method has been used before to identify the Pt atoms and calculate the number of atoms from the determined volume of a Pt sphere [10]. The stability and catalytic properties of nanoparticles may be improved by combing two or more metallic elements [11,12,13].…”

Component‐Tunable Rutile‐Anatase TiO2/Reduced Graphene Oxide Nanocomposites for Enhancement of Electrocatalytic Oxygen Evolution

“…As an earth‐abundant and environment‐friendly material, TiO 2 can be served as good photocatalyst or photo‐electro‐catalyst ,,,. However, it is not a good electrocatalyst for OER due to a corresponding high overpotential.…”