Freestanding Penta-Twinned Palladium Nanosheets.

Control over the morphology of nanomaterials to have a 2D structure and manipulating the surface strain of nanostructures through defect control have proved to be promising for developing efficient catalysts for sustainable chemical and energy conversion. Here a one-pot aqueous synthesis route of freestanding Pd nanosheets with a penta-twinned structure (Pd NSs) is presented. The generation of the penta-twinned nanosheet structure can be succeeded by directing the anisotropic growth of Pd under the controlled reduction kinetics of Pd precursors.

Directing Energy Flow in Core-Shell Nanostructures for Efficient Plasmon-Enhanced Electrocatalysis.

Conjugating plasmonic metals with catalytically active materials with controlled configurations can harness their light energy harvesting ability in catalysis. Herein, we present a well-defined core-shell nanostructure composed of an octahedral Au nanocrystal core and a PdPt alloy shell as a bifunctional energy conversion platform for plasmon-enhanced electrocatalysis. The prepared Au@PdPt core-shell nanostructures exhibited significant enhancements in electrocatalytic activity for methanol oxidation and oxygen reduction reactions under visible-light irradiation.

Role of Surface Strain at Nanocrystalline Pt{110} Facets in Oxygen Reduction Catalysis.

We have developed a synthesis method of rhombic dodecahedral Pd@Pt core-shell nanocrystals bound exclusively by {110} facets with controlled numbers of Pt atomic layers to study the surface strain-catalytic activity relationship of Pt{110} facets. Through control over growth kinetics, the epitaxial and conformal overgrowth of Pt shells on the {110} facets of rhombic dodecahedral Pd nanocrystals could be achieved. Notably, the electrocatalytic activity of the Pd@Pt nanocrystals toward oxygen reduction reaction decreased as their Pt shells became thinner and thus more in-plane compressive surface strain was applied, which is in sharp contrast to previous reports on Pt-based catalysts.

Fine Control over the Compositional Structure of Trimetallic Core-Shell Nanocrystals for Enhanced Electrocatalysis.

Pt-based multimetallic nanocrystals (NCs) have attracted tremendous research interest because of their excellent catalytic properties in various electrocatalysis fields. However, the development of rational synthesis approaches that can give multimetallic NCs with desirable compositional structures is still a radical issue. In the present work, we devised an efficient strategy for the systematic control of the spatial distribution of constituent elements in Pt-based trimetallic core-shell NCs, through which NCs with distinctly different compositional structures, such as Au@PdPt, Au@Pd@Pt, AuPd@Pt, and AuPdPt@Pt core-shell NCs, could selectively be generated.