1 research outputs found
Modulating Surface Composition and Oxygen Reduction Reaction Activities of Pt–Ni Octahedral Nanoparticles by Microwave-Enhanced Surface Diffusion during Solvothermal Synthesis
Compositional
segregations in shaped alloy nanoparticles can significantly
affect their catalytic activity and are largely dependent on their
elemental anisotropic growth and diffusion during nanoparticle synthesis.
An efficient approach to control the surface segregations while keeping
the nanoparticle shape are highly desired for fine-tuning their catalytic
properties. Using octahedral Pt–Ni nanoparticles as a typical
example, we report a new strategy to modulate the surface composition
of shaped bimetallic nanoparticles by microwave-enhanced surface diffusion
during solvothermal synthesis. Compared to traditional solvothermal
synthesis, the application of microwave significantly promotes atomic
diffusion, particularly surface diffusion, within the Pt–Ni
octahedrons, leading to Pt segregation on the {111} facets while largely
keeping the octahedral shape. The obtained segregated Pt–Ni
octahedral nanoparticles performed excellent activity toward oxygen
reduction reaction. The revealed microwave-enhanced surface diffusion
in a liquid phase provides a new way to modulate surface compositions
of bimetallic alloy nanoparticles at relatively lower temperatures
compared to the widely adopted high-temperature gas-phase thermal
annealing