Jisun Yoon

One-pot synthesis of ultralong coaxial Au@Pt nanocables with numerous highly catalytically active perpendicular twinning boundaries and Au@Pt core–shell bead structures

Ultralong coaxial Au@Pt nanocables prepared by one-pot synthesis exhibit excellent electrocatalytic activity due to structural features of (1) numerous twinning boundaries and (2) lattice mismatch between the core and the shell.

Axially twinned nanodumbbell with a Pt bar and two Rh@Pt balls designed for high catalytic activity

A fail-proof synthetic strategy has been developed for a multiply twinned dumbbell-shaped Rh@Pt nanostructure, which exhibits a superior electrocatalytic activity for methanol oxidation reaction. The unusually high electrocatalytic activity has been attributed to the synergistic effects of crystal twinning and core-shell structure.

Fabrication of hierarchical Rh nanostructures by understanding the growth kinetics of facet-controlled Rh nanocrystals

By understanding the structural relationship among three shape-controlled Rh nanostructures, namely, {111} nanotetrahedrons, {111} tetrahedral nanoframes, and <111> skeletal nanotetrapods, we could prepare novel hierarchical dendritic Rh nanostructures with <111> Rh arms as linkers between tetrahedral shaped nanocrystals.

Twinning boundary-elongated hierarchical Pt dendrites with an axially twinned nanorod core for excellent catalytic activity

Twinning boundary-elongated hierarchical Pt nanostructures with excellent electrocatalytic activity were prepared by using axially twinned Pt3Ni nanorods as the platform for epitaxial transfer of a twinned crystal structure. The high electrocatalytic activity of the hierarchical nanostructures results from the synergistic effects of lattice mismatch between the Pt3Ni core and the Pt shell and the elongated twinning boundary.

Synthesis of bare Pt3Ni nanorods from PtNi@Ni core–shell nanorods by acid etching: one-step surfactant removal and phase conversion for optimal electrochemical performance toward oxygen reduction reaction

Pt–Ni alloy, most notably Pt3Ni phase, nanoparticles synthesized using a surfactant-assisted solution phase route have shown great promise as electrocatalysts toward the oxygen reduction reaction (ORR) for fuel cells. Surfactant removal without deteriorating the catalytic performance of alloy nanocrystals has been an ongoing issue in this research area. Herein, we report a convenient preparation route to surfactant-free Pt3Ni nanorods from PtNi@Ni nanorods assisted by acid etching as well as their excellent electrocatalytic activity for ORR.

One-pot synthesis of a highly active, non-spherical PdPt@Pt core–shell nanospike electrocatalyst exhibiting a thin Pt shell with multiple grain boundaries

Co-decomposition of Pd and Pt precursors in the presence of trioctylphosphine and stearic acid gives a unique non-spherical PdPt@Pt core–shell nanospike with multiple grain boundaries in a facile one-pot synthesis. The difference in the metal–P bond strengths causes the disparate precursor decomposition kinetics, which in turn positions the Pt content on the nanoparticle surface. The core–shell composition, crystallinity, and shell thickness are conveniently controlled by simple variations in the amount of precursors and surfactants. The PdPt@Pt core–shell nanospike shows a high electrocatalytic activity toward methanol oxidation reaction. The excellent catalytic performance seems to originate from (1) the existence of multiple, surface energy-elevating grain boundaries, (2) roughened surface, and (3) lattice mismatch between the core and shell.